A Vegetative Key to Landscape Plants
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This key has as its original framework the key and work of Donald Pinkava and Elinor Lehto of the Arizona State University.  The goal is to make there work more useful and helpful to those attempting to identify plants in the Valley of the Sun.

KEY OUTLINE

Cacti Section 1
Palms and Palm Like Plants Section 2
Grasses (including Bamboos) and Grass-Like Plants Section 3
Yuccas and Yucca-Like Plants Section 4
Leaves Bladeless (Needles, Scales, Bristles) Section 5
Leaves absent most of the year, drought conditions Section 6
Vines Section 7
Leaves Broad (Plants not of categories above) Section 8
 Leaves compound or appearing so Section 8A
  Leaves simple Section 8AA
   Leaves whorled or opposite Section 8B
    Leaves alternate Section 8BB
     Plants armed with thorns, spines or prickles Section 8C
      Plants unarmed Section 8CC
       Margins lobed, serrate, dentate, etc. Section 8D
       Margins entire or undulate Section 8DD

 

Cacti Section 1
1 Plants succulent, with areoles; leaves modified into spines, or glochids, or fleshy cones which are soon deciduous, or sometimes absent: Cactus Family 2

Plants sometimes succulent, not with areoles; leaves variable, evergreen or deciduous 29

 

2 1 Areoles bearing glochids; stems jointed, cylindric or flattened, not ribbed, not bearing prominent tubercles.  3

Areoles not bearing glochids; stems cylindric, sometimes bearing joints, ribs or prominent tubercles. 16

 

 

3 2  Joints cylindric; spines sheathed when young: Chollas 4

 

Joints flattened (pads), spines not sheathed 9

 

4 3  Lateral joints Ό” in diameter, 1-3” long; Plant bushy Cylindropuntia leptocaulis

 

Lateral joints ½” or more in diameter, over 3” long 5

 

5 4 Branchlets Ύ” or more in diameter, bearing elongate, low tubercles    6

 

Branchlets to ½” in diameter, smooth or bearing obscure tubercles; plant arborescent at maturity Opuntia arbuscul

 

6 5 Branches in whorls; plants arborescent Opuntia spinosior

 

Branches not in whorls; plants sometimes arborescent 7

 

7 6 Plants arborescent, much branched; spines straw-colored 8

 

Plants sprawling shrubs, loosely branched; spines dark to light, but not straw-colored Opuntia acanthocarpa

 

8 7 Plants to 6’ tall; terminal joints short, very easily dislodged; fruits not in chains Opuntia bigelovii
 

Plants to 12’ tall; terminal joints longer, not as easily dislodged; fruits persisting in chains (variety with fewer and shorter spines on more prominent tubercles is mammillata Opuntia fulgida

 

9 3 Joints broad, flattened, alternate or irregularly arranged; Prickly Pears 10
Joints narrow, flattened, whorled Nopalea cochinellifera

 

10 9 Joints 3-4 times longer than wide, tapering to a long slender tip Opuntia linguiformis

 

Joints not more than twice as long as wide, orbicular to obovate 11

 

11 10  Central spines present, stout, whitish or yellowish Opuntia phaecantha var. discata

 

Central Spines, if present, not stout, yellowish to reddish 12

 

12 11 Plants arborescent, with distinct trunks 13

 

Plants shrubs, not with distinct trunks 15

 

13 12 Pads very thick; glochids few, scarcely visible; areoles widely spaced Opuntia ficus-indica
 

Pads less than Ύ” thick; glochids numerous, obvious; areoles closely spaced 14

 

14 13 Pads about ½” thick, green to blue-green Opuntia chlorotica


Pads about Ό” thick, green turning purplish during cold or dry seasons Opuntia santa-rita

 

15 12 Plants to 1 ½’ tall, mostly one joint high; joints obovate, gray, wrinkled, with abundant red glochids Opuntia basilaris


Plants to 4’ tall, several joints high; joints oblong to orbicular, green, velvety, with abundant red to white glochids Opuntia microdasys

 

16 2 Stems weak, arching or trailing, with long slender joints 17


Stems erect 20

 

17 16 Stems gray, angled with 3-6 prominent longitudinal ribs bearing blackish spines less than 1/8” long Cereus greggii

 

Stems green (or purplish), ribbed but not angled; spines white or yellow to gray, more than Ό” long 1 ??

 

18 17 Spines ½” (or less) long; ribs not prominent Selenicereus grandiflorus


Spines 1” long or longer; ribs prominent 19

 

19 18 Older stems approximately 3” in diameter, turning red during cold or dry periods, branching near the base Rathbunia alamosensis

 

Older stems approximately 2” in diameter, green, branching above the base Harrisia eriophora

 

20 16 Stems columnar, 6’ or more tall, ribbed; spines terete, straight (in one form absent) 21


Stems less than 6’ tall, or if more, then at least certain spines definitely curved and flattened 23

 

21 20 Plant branching well above the constricted base Cereus giganteus

 

Plant branching near the unconstricted base, sometimes also above 22

 

22 21 Ribs numerous, 12-17; spines uniform throughout plant Cereus thurberi


Ribs fewer, 5-7; spines not uniform throughout plant; mature branch tips with areoles bearing numerous flexuous spines(or spines absent; areoles few; rounded protruberences forming irregular ribs in forma monstrosusCereus schottii

 

23 20 Plants with prominent tubercles not arranged in longitudinal ribs 24

 

Plants with longitudinal ribs 25

 

24 23 Tubercles grooved above; central spine straight Coryphantha arizonica

 

Tubercles not grooved; central spine hooked Mammillaria microcarpa

 

25 23 Spines straight or slightly curved, but not hooked or distinctly twisted 26

 

At least some of the spines hooked or distinctly twisted 28

 

26 25 Plants cylindric, branching mostly at or below soil line Echinocereus engelmannii

 

Plants globose, solitary or branched at base or above 27

 

27 26 Spines terete, dark-colored; plants often branched above base, apex not depressed, not woolly Echinopsis

 

Spines flattened, golden yellow; plants solitary or branched at base; apex depressed, woolly Echinocactus grusonii

 

28 25 Plants nearly as wide as tall; central spines not twisted, sometimes hooked Ferocactus wislizenii
 

Plants much taller than wire; central spines twisted, often hooked Ferocactus acanthodes

 

Palms and Palm Like Plants Section 2

 

29 1 Plants palms or palm-like (some without trunks) 30

 

Plants not palm-like 53

 

30 29 Leaves palmately veined;  Fan Palms 31

 

Leaves pinnately veined; Feather Palms 43

 

31 30 Trunks clustered, usually dward to 10’ tall, often hidden in foliage 32

 

Trunks solitary, of various heights 33

 

32 31 Blades deeply divided into 5-10 segments, almost as leaflets (appearing like dwarf bamboo); petioles not armed or irregularly so Rhapis excelsa

 

Blades not deeply divided to appear as leaflets; petioles distinctly armed with teeth Chamaerops humilis

 

33 31 Palms dwarf; trunk to 4’ tall; blades deeply divided into two equal parts, each with minor divisions; petioles not armed Sabal minor

 

Palms not dwarf; trunks to 10’ or more tall; blades not deeply divided into two parts; petioles armed or not 34

 

34 33 Midvein decidedly curled downward and backward; petiole not with marginal teeth 35

 

Midvein little or not at all curled downward and backward; petioles with or without marginal teeth  36

 

35 34 Leaf blades to 6’ across; inflorexcence shorter than petiole; fruit about ½” in diameter Sabal palmetto

 

Leaf blades to 4’ across; inflorescence longer than petiole; fruit about 3/8” in diameter. Sabal mexicana

 

36 34 Very long, stout spines terminating stiff network of old leaf sheaths. Trithrinax acanthocoma

 

No stout spines terminating old leaf sheaths 37

 

37 36 Leaf blades with sharply drooping segments Fountain Palms 38

 

Leaf blades not with sharply drooping segments 39

 

38 37 Trees to 60’ tall; leaves soft green; petioles armed. Livistona australis

 

Trees to 30’ tall; leaves bright shiny green; petioles sometimes armed.  Livistona chinensis

 

39 37 Petiole smooth (or with few small teeth at base) Erythea edulis

Petiole with marginal teeth 40

 

40 39 Petiole with very fine teeth; trunk with very many hair-like fibers. Trachycarpus fortunei

Petiole with coarse teeth; trunk not with very many hair-like fibers (though some may be present) 4 ??

 

41 40 Leaves blue-glaucous.  Erythea armata

Leaves green or gray-green 42

 

42 41 Trunks short to medium height, stout, about 2’ or more in diameter at middle; blades very filiferous at maturity Washingtonia filifera

Trunk tall, slender, about 1’ in diameter at middle; blades little filiferous. Washingtonia robusta

 

43 30 Leaves coiled upon unfolding from bud (circinnate venation); leaf segments (pinnae) with revolute margins 43a

Leaves flat or folded lonitudinally in bud; pinnae not with revolute margins 44

 

43a 43 Leaflets with prominent midveins Cycas revoluta

Leaflets not with a prominent midvein Dioon edule

 

44 43 Lower pinnae represented by stiff, long, folded spines 45

Lower pinae not developed into spines 48

 

45 44 Trunks clustered, usually dwarf 46

Trunks solitary, not dwarf 47

 

46 45 Leaves white floccose in interrupted lines on ribs beneath Phoenix reclinata

Leaves not white floccose beneath Phoenix roebelenii

 

 

47 45 Trees slender to 100’ tall, with a rather dense crown of green to bluish green leaves, often glaucous; fruit cylindric, 1-2” long, edible; seed more than 3 times longer than wide Phoenix dactylifera

Trees stout, to 60’ tall, with a dense crown of green to light green leaves;, fruit about Ύ” long, not considered edible; seed less than 3 times longer than wide Phoenix canariensis

 

48 44 Pinnae tips erose (jagged); leaflets rigid, many-veined, broadened at apex. Ptychosperma elegans


Pinnae tips pointed, not erose; leaflets various 49

 

 

49 48 Leaves blue-glaucous, arching, petiole spiny at base. Butia capitata

 

Leaves green; petiole not spiny 50

 

50 49 Shrubby trees to 8’ tall; pinnae to 20 pairs in number Chamaedorea elegans

 

Trees 20-50 feet or more tall; pinae many, 40 pairs or more 51

 

51 50 Petiole fibrous shaggy Syagrus romanzoffianum

 

Petiole not fibrous shaggy 52

 

52 51 Pinnae with lateral veins prominent above, chaffy on midvein and margins beneath, at least when young; stems branching at maturity; leaf rachis yellow to red beneath. Chrysalidocarpus lutescens
 

Pinnae with lateral vines prominent beneath, coarsely chaffy on only midvein beneath; leaf rachis slightly grayish beneath; stems not branching. Archontophoenix cunninghamiana

         

Grasses (including Bamboos) and Grass-Like Plants Section 3

 

53 29 Plants grasses (including bamboos) or grass-like; leaves parallel veined, ensheathing stems 54


Plants not grass-like; leaves various but not parallel veined and ensheathing stems. 67

    

54 53 Plants aquatic or semiaquatic; leaves strongly ascending; Cattails Typha latifolia


Plants terrestrial; leaves not strongly ascending 55

 

55 54 Culms(stems) terete, jointed, or various heights; all leaf sheaths with blades, these sometimes deciduous 56


Culms angled slightly, but not jointed, 2-4' tall, stout, bearing many long, firm, spreading leaves at the apex (like umbrella ribs); basal leaf sheaths bladeless Cyperus alternifolius

 

56  55 Blades much broader than the sheath, stalked, deciduous from the joint at sheath; sheaths sometimes persistent Bamboos 57


Blades narrower than or as broad as the sheaths, not stalked; blades and sheaths persistent 65

 

57 56 Culms flattened on one side above the node 58


Culms terete throughout 60

 

58 57 Culms becoming black


Culms becoming yellow or golden 59

 

59 58 Culms flattened on one side above node Phyllostachys aurea


Culms grooved on one side above node Phyllostachys aureosulcata

 

60 57 Culms to about 3' tall, from running rhizomes, not clumping 61


Culms 5' or more tall, sometimes in dense clumps 62

 

61 60 Internodes solid, short; culms to 1 foot tall, purplish Arundinaria pygmae


Internodes hollow, long; culms to 3' tall(leaves green or variegated) Arundinaria variegata

 

62 60 Rhizome internodes with many scattered roots developing; culms with several branches at a node; sheath bristles stiff, scabrous 63


Rhizome internodes with a single band or row of roots developing; culms with one or two branches at a node; sheath bristles flexuous, not scabrous Pseudosasa japonica

 

63 62 At least some internodes swollen in the middle (intensifies if pot-bound) Bambusa ventricosa

Internodes not swollen in the middle 64

 

64 63 Stems to 60' or more tall, 2-4" in diameter at maturity, deep green Sinocalamus oldhamii


Stems to 35' tall, 1" in diameter, often striped green, yellow or pink Bambusa multiplex

 

65 56 Leaf margins finely serrate (serrulate) 66


Leaf margins entire, smooth Arundo donax

 

66 65 Culms 18-36" tall, less than 1/8" in diameter, scabrous below the inflorescence; inflorescence narrow, to 12" long Pennisetum setaceum

 
Culms 4-20' tall, about 1/4" or more in diameter, glabrous throughout; inflorescence open, plume-like, to 2' long Cortaderia selloana

 

Yuccas and Yucca-Like Plants Section 4

 

67 53 Plants yuccas or yucca-like, often scapose; leaves in a rosette, basal or atop a trunk (occasionally well distributed along trunk in young plants), often linear, sometimes succulent 68


Plants neither scapose nor with a rosette of leaves 77

 

68 67 Leaves with marginal prickles 69


Leaves not with marginal prickles, but sometimes finely serrate (serrulate) 71

 

69 68 Leaves very succulent, usually spotted with a lighter color; no fibers in center of leaf; basal rosette to 2' in diameter Aloe spp.


Leaves not succulent or succulent fibers in the center of the leaf; basal rosette usually larger than 2' in diameter 70

 

70 69 Blades thin, to 1" wide, about 3' long, tapering to long foliaceous tips; margins bearing numerous tiny recurved prickles Dasylirion wheeleri


Blades thick, succulent, with strong central fibers, to 6" or more wide, about 4' long, with stout spines at tips; margins bearing relatively few but large prickles (variety with white or yellow margined leaves is marginata) Agave americana

 

71 68 Leaf margins serrulate to entire 72


Leaf margins filiferous 75

 

72 71 Leaves rigid, dagger-like 73


Leaves flexible, lower leaves recurved or drooping 74

 

73 72 Leaves to about 8" long, about 1/2" wide; arborescent, much branched Yucca brevifolia


Leaves to about 1' or more long, about 3/4" or more wide; sometimes arborescent, little branched Yucca aloifolia

 

74 72 Arborescent, stems often with swollen bases; leaf margins sharply serrate Yucca elephantipes


Stems short, not noticeably swollen at bases; leaf margins entire or irregularly serrulate to undulate Yucca recurvifolia

 

75 71 Plants at maturity with trunks; leaf blades flat, narrow, with many fine fibers Yucca elata


Plants at maturity not with trunks, or if so, then not erect; leaf blades concave, narrow to broad, with few and coarse fibers 76

 

76 75 Leaf blades more than 1" wide, to 2' long; inflorescence rigid, dense, little exceeding the foliage Yucca baccata


Leaf blades to 3/4": wide to 4' long; inflorescence limber, open, greatly exceeding the foliage Hesperaloe parviflora

 

Yucca rostrata Yucca thompsoniana Yucca pallida Yucca rupicola Yucca carnerosana Yucca grandiflora
Leaves Bladeless (Needles, Scales, Bristles) Section 5

 

77 67 Leaves sessile, bladeless, appearing needle-like or scale-like (appressed flattened or subulate) or bristle-like; leaves present during the growing season 78


Leaves sessile or not, blades flattened, sometimes with revolute margins; leaves present or absent during the growing season 97

 

78 77 Leaves fascicled, needle-like or filiform 79


Leaves not fascicles; needle-like, scale-like or bristle-like 84

 

79 78 Vines or shrubs, armed along main axes; leaves (actually modified stems called cladodes) to 1" long 80


Trees, unarmed; leaves 1" or more long 81

 

80 79 Vines or trailing shrubs, branchlets much flattened, triangular in outline, fern-like; cladodes of branchlets mostly about 1/4" long Asparagus plumosus


Upright shrubs, branchlets not flattened; cladodes of branchlets mostly 1/2" or more long Asparagus retrofractus

 

81 79 Fascicles not sheathed; needles falling singly Cedrus deodara


Fascicles sheathed; needles falling in clusters Pines 82

 

82 81 Needles 2 per fascicle, 2-6" long; sheaths to 1/2" long 83


Needles 3 per fascicle, 8-12" long; sheaths to 3/4" long Pinus canariensis

 

83 82 Sheath ending in two long filaments; cones deciduous Pinus thurberiana


Sheath not ending in two long filaments; cones persistent Pinus halepensis

 

84 78 Branchlets appearing jointed, internodes longer than leaves 85


Branchlets not appearing jointed, internodes shorter than the leaves 87

 

85 84 Shrubs; branchlets stout, ascending; leaves opposite, shredding at maturity Ephedra fasciculata


Trees; branchlets fine, flexuous; leaves alternate or whorled, minute 86

 

86 85 Leaves alternate, reduced to mere obtuse protuberances Tamarix aphylla


Leaves in whorls of 5-9, acute, fused below Casuarina cunninghamiana

 

87 84 Leaves alternate 88


Leaves opposite or whorled 89

 

88 87 Major branches alternate; branchlets fine, shrubs 88a


Major branches whorled; branchlets not fine, slightly or not glaucous; trees; leaves more than 1/3' long Araucaria heterophylla

 

88a 88 Shrubs to 20' tall; leaves to 1/2" long Tamarix pentandra

Shrubs to 3' tall; leaves 1" or more long Grevillea noelli

 

89 87 Branchlets flattened, arranged in vertical planes Thuja orientalis


Branchlets not flattened, or if so, then not arranged in vertical planes 90

 

90 89 Trees; leaves scale-like, not subulate; cones woody, persistent, dehiscent, with many seeds under peltate scales Cypresses 91


Trees or shrubs; leaves all scale-like or all subulate or mixed; cones berry-like, indehiscent, scales fused with 1-few seeds; Junipers 92

 

91 90 Trees pyramidal to columnar Cupressus sempervirens


Trees with spreading branches, not pyramidal, not columnar (smooth, red-barked form with exfoliating bark often called C. glabra) Cupressus arizonica

 

92 90 Leaves with a strong disagreeable odor when crushed Juniperus sabina


Leaves not with a disagreeable odor when crushed 93

 

93 92 Leaves all( or nearly all) subulate 94

Leaves of two kinds, scale-like and subulate, or all scale-like 95

 

94 93 Leaves opposite (in whorls of 3 on vigorous new growth); low spreading or trailing shrubs, grayish green turning purplish in winter Juniperus horizontalis


Leaves mostly in whorls of 3; trees or shrubs, sometimes creeping; green or blue-green (includes J. procumbens) Juniperus chinensis

 

95 93 Leaves all or nearly all scale-like, obtuse to acute, opposite, or if also with subulate leaves, these in whorls of 3, at least on older branch axes; berry-like cone brownish, glaucous, 1/4" or more in diameter (numerous forms including cv. 'Torulosa' which has deep green clustered branchlets; cf. 'Pfitzeriana' which is shrubby with horizontally spreading branches. Juniperus chinensis


Leaves both scale-like and subulate; scale-like leaves acute to acuminate, opposite; subulate leaves mostly opposite; berry-like cone blackish, glaucous, 1/4" or less in diameter 96

 

96 95 Gland on lower scale leaf surface small, shorter than distance from gland to leaf apex Juniperus virginiana


Gland on lower scale leaf surface elongate, equal to or longer than distance from gland to leaf apex Juniperus scopulorum

 

Leaves absent most of the year, drought conditions Section 6

 

97 77 Leaves absent because of drought conditions, but with evidence of former leaves such as leaf scars, and persisting petioles or rachises 98


Leaves evergreen or at least present during the growing season 107

 

98 97 Plants with spines 99


Plants not with spines, but with or without stout branches, these sometimes modified into thorns 101

 

99 98 Paired stipular apines present; rachises of compound leaves usually persisting, primary rachis short, ending in a sharp spine; secondary rachises 2-3 pairs, 8" or more long Parkinsonia aculeata


Spines not paired, formed from persistent petioles after loss of blade of simple leavs 100

 

100 99 Plant branching from near the base into many wand-like branches bearing greenish stripes or patches Fouquieria splendens


Plant with large, inverted carrot-shaped trunk, branching throughout, branches short, horizontal, not bearing greenish stripes or patches Idria columnaris

 

101 98 Branches stout, thorny; plants intricately branched 102


Branches neither stout nor thorny; if plant is intricately branched, then the branches are narrowly winged 105

 

102 102 Shrubs; branches tan, brown or gray 103


Trees; branches green 104

 

103 102 Plants silvery gray with abundant straight gray hairs; branches with dark sharpened tips and additional lateral thorns Condalia lycioides


Plants tan or brownish with appressed hairs; branchlets only slightly thorny, tips not darkened, not with lateral thorns Lycium exsertum

 

104 102 Branches yellowish green Parkinsonia microphyllum


Branches bluish green Parkinsonia florida

 

105 101 Stems green, woody; leaf scars alternate 106


Stems gray, brittle, only slightly woody at base (sufrutescent); leaf scars opposite Justicia californica

 

106 105 Plants intricately branched; branches narrowly winged, viscid-glandular Baccharis sarothroides


Plants with long, terete, wand-like branches, not viscid-glandular Spartium junceum

 

Vines Section 7

 

108 107 Plants with tendrils 109


Plants not with tendrils ( but sometimes bearing roots along the stems ) 119

 

109 108 Leaves compound 110


Leaves simple 115

 

110 109 Leaves alternate, palmately compound or trifoliate 111


Leaves opposite, compound and 3-parted, center leaflet reduced to a tendril ( sometimes leaves simple or with 2-3 non-tendril leaflets) 113

 

111 110 Leaflets usually 5, thin, not fleshy; tendrils ending in flattened disks Parthenocissus quinquefolia


Leaflets usually 3 or 5, fleshy; tendrils not ending in a flattened disk 112

 

112 111 Leaflets usually 5 Cissus hypoglauca


Leaflets 3 Cissus rhombifolia

 

113 110 Tendril simple; lateral leaflets obtuse to acute Clytostoma callistegioides


Tendril 3-cleft; lateral leaflets acuminate 114

 

114 113 Tendril sharp-clawed, not longer than the lateral ovate to lanceolate or oblanceolate leaflets Doxantha unguis-cati


Tendril not sharp-clawed, much longer than the lateral cordate-deltoid leaflets Pithecoctenium cynanchoides

 

115 109 Leaves heart-shaped; not lobed; margins undulate or crenate Antigonon leptopus


Leaves lobed 116

 

116 115 Leaf margins shallowly to deeply lobed, lobes acutely toothed or jagged; petioles not with glands Vitis vinifera


Leaf margins deeply 3-5 lobed, lobes entire or serrate; petioles with 2-4 glands 117

 

117 116 Leaf margins 5 lobed Passiflora caerulea


Leaf margins 3 lobed 118

 

118 117 Lobes entire, dull above; stem angled, not grooved Passiflora x alato-caerulea


Lobes irregularly serrate, glossy above; stem grooved Passiflora edulis

 

119 108 Leaves pinnately compound 120


Leaves simple (sometimes deeply lobed) 122

 

120 119 Leaflet margins serrate or dentate 121


Leaflet margins entire or undulate Wisteria sinensis

 

121 120 Leaves opposite; leaflets 9-13, pubescent beneath, dentate Campsis radicans


Leaves alternate; leaflets 5-7, glabrous beneath or very nearly so, serrate Rosa banksiae

 

122 119 Stems armed with thorns or spines 123


Stems not armed 125

 

123 122 Leaves (actually modified stems called cladodes ) linear, often fascicles; stems with spines (modified bracts) along main axes 124


Leaves ovate, acuminate, not fascicled; stems with thorns Bougainvillea spectabilis

 

124 123 Cladodes about 1" long, straight or nearly so, margins not noticebly crisped Asparagus densiflorus sprengeri


Cladodes about 2-3" long, often sickle-shaped (falcate), margins noticeably crisped Asparagus falcatus

 

125 122 Leaves opposite 126


Leaves alternate 129

 

126 125 Petioles bearing 2 minute glands at base of blade Vinca major


Petioles not bearing glands 127

 

127 126 Petioles jointed Jaminum nitidum

 

Petioles not jointed 128

 

128 127 Plants with milky sap 128a

 

Plants not with milky sp 128a

 

eaves acute to acuminate, lower lateral veins directed forward along margins; plants not with milky sap Gelsemium sempervirens


Leaves abruptly narrowed to blunt (sometimes pointed) tips, lower lateral vines not directed far forward along margins; plants usually with milky sap Trachelospermum jasminoides

 

128a 128 Small teeth borne along stipular ridge between opposing leaves of branchlets Trachelospermum jasminoides

Small teeth confined to bases of petioles, not borne all along stipular ridge Periploca graeca

 

128b 128 Stipular ridge between opposing leaves of branchlets bearing teeth Gelsemium sempervirens

Stipular ridge not bearing teeth (immature leaves of var. chinensis purple-tinted) Lonicera japonica

 

129 125 Leaf margins ( at least some of them ) palmately lobed or dissected 130


Leaf margins entire 133

 

130 129 Leaf margins deeply dissected; stems hirsute Ipomoea dissecta


Leaf margins lobed, not deeply dissected; stems sometimes pubescent but not hirsute 131

 

131 130 Leaf blades deltoid, usually shallowly 3-lobed Hedera canariensis


Leaf blades not deltoid, usually 5-lobed 132

 

132 131 Petioles with sessile stellate hairs only; leaf blades to 3" broad Hedera helix


Petioles with branching upright hairs; leaf blades to 6" broad; stems usually stout, often shrubby Fatshedera lizei

 

133 129 Plants dimorphic; vegetative stage with stems adhering flat to supporting wall, leaf blades to 1" long, cordate-ovate, inequilateral; fruiting stage with branches stiff and erect, leaf blades 2-4" long, elliptic to oblong-elliptic, inequilateral.  Vines woody, milky Ficus pumila


Plants not dimorphic; vines nearly herbaceous, not milky 134

 

134 133 Leaf blades thin, somewhat crinkled, with sheathing stipules Polygonum aubertii


Leaf blades fleshy and smooth, not with sheathing stipules Boussingaultia gracilis var. pseudo-basselloides

 

Leaves Broad (Plants not of categories above) Section 8
 Leaves compound or appearing so Section 8A

 

135 107 Leaves compound or so deeply divided as to appear compound 136


Leaves simple 202

 

136 135 Leaf margins deeply dissected and appearing pinnately compound 137


Leaves regularly compound with distinct leaflets 140

 

137 136 Subshrubs; leaf blades 1/2' to 1 1/2" long, pinnately divided into minute segments arranged in 4 rows; herbage aromatic when crushed 138


Trees or shrubs; leaf blades not divided into minute segments arranged in 4 rows 139

 

138 137 Plants silvery gray, tomentose Santolina chamaecyparissus


Plants green, glabrous Santolina virens

 

139 137 Trees to 150' tall; leaves alternate, leaf blades more than 6" long, with secondary lobes entire or again lobed, silky beneath, margins revolute Grevillea robusta


Shrubs to 10' tall; leaves opposite; leaf blades to 5" long, once-loved (some often unlobed), not silky beneath, margins not revolute Syringa laciniata

 

140 136 Leaves pinnately compound or leaflets 2 or 3 141


Leaved palmately compound, leaflets more than 3 198

 

141 140 Leaflets 2 (bifoliate), rachis slightly prolonged between the leaflets, leaflets confluent at bases Larrea divaricata


Leaflets more than 2 142

 

142 141 Leaflets 3 (trifoliate) 143


Leaflets more than 3 (occasionaly some trifoliate) 147

 

143 142 Petioles with recurved prickles Erythrina crista-galli


Petiole not with prickles 144

 

144 143 Stems armed with thorns; petioles broadly winged, jointed at base of blade Poncirus trifoliata


Stems not armed; petioles, if winged, not jointed at base of blade. 145

 

145 144 Leaves alternate; trees or shrubs 146


Leaves opposite; shrubs with slender branches arching to the ground Jasminum mesneyi

 

146 145 Trees; leaflets lanceolate, 2" or more long Rhus lancea


Shrubs; leaflets obovate, to about 1/2" long Citisus racemosus

 

147 142 Leaves once compound 167


Leaves more than once compound 148

 

148 147 Leaves three or four times compound 149


Leaves twice compound 150

 

149 148 Leaflets entire; petioles clasping; shrubs Nandina domestica


Leaflets serrate to dentate; petioles not clasping; trees Melia azerdarach

 

150 148 Leaflet margins obviously crenate, serrate or dentate 151


Leaflet margins entire ( or sometimes ciliate ) 152

 

151 150 Leaflets acuminate, coarsely serrate to dentate; leaves odd-pinnate, twice or thrice compound; trees unarmed Melia azerdarach


Leaflets obtuse to acute, not acuminate, finely serrate or crenate; leaves even-pinnate, once or twice compound; trees armed with large, stout, simple or branched thorns (or without thorns forma inermis ) Gleditsia triacanthos

152 150 Leaves opposite Jacaranda acutifolia


Leaves alternate 153

 

153 152 Petiole bearing a small gland above, located from base to between lowest primary pinnae 154


Petiole not bearing glands 159

 

154 153 Nodes of older branches knobby; branches often zig-zag, usually armed with stipular spines 155


Nodes not knobby; branches not noticeably zig-zag, armed or not 156

 

155 154 Leaves glabrous; leaflets usually more than 5 times longer than wide Prosopis glandulosa


Leaves pubescent; leaflets usually less than 5 times longer than wide Prosopis velutina

 

156 154 Primary leaflets 1-3 pairs; stems armed with stipular spines Ebenopsis flexicaule


Primary leaflets 4-12 pairs; stems not armed 157

 

157 156 Shrubs or sprawling trees; branches flattened, fern-like; stipules when present broad, leafy Lysiloma thornberi


Trees; branches not fern-like; stipules narrow, not leafy 158

 

158 157 Trees flat-topped; leaflet midvein submarginal; flowers pinkish, spring blooming Albizia julibrissin


Trees not flat-topped; leaflet midvein submedian; flowers white, fall-blooming Leucaena leucocephala

 

159 153 Primary leaflets 1-5 (-6) pairs; stipular spines present or not 160


Primary leaflets 6-many pairs; stipular spines absent 165

 

160 159 Primary rachis short, ending in a spine; primary leaflets 2-3 pairs, 8 inches or more long, with numerous tiny secondary leaflets; stipular spines present Parkinsonia aculeata


Primary rachis not ending in a spine; primary leaflets to 4" long 161

 

161 160 Main branches green or blue-green 162


Main branches dark, brownish or grayish 163

 

162 161 Bark of main branches yellow-green; secondary leaflets very tiny, 5-6 pairs per secondary rachis Parkinsonia microphyllum


Bark of main branches blue-green; secondary leaflets to 1/3" long, 2-3 pairs per secondary rachis Parkinsonia florida

 

163 161 Shrubs, not armed Calliandra tweedii


Trees or shrubs, armed 164

 

164 163 Primary leaflets 4-5 pairs; secondary leaflets numerous, terminal ones oblong to narrowly elliptic; stipular spines paired, straight Acacia farnesiana


Primary leaflets 1-3 pairs; secondary leaflets few, terminal ones obovate; prickles solitary, recurved Acacia greggii

 

165 159 Small trees; leaves large, often 1 1/2' or more long Delonix regia


Shrubs; leaves smaller, usually less than 1' long 165a

 

165a 165 Secondary leaflets small (about 1/16" long); stipules narrow and spinescent Acacia millefolia

Secondary leaflets larger (about 1/4" or more long); stipules not spinescent 166

 

166 165 New growth not with stalked glands, not foetid; stems sometimes with prickles Caesalpinea pulcherrima


New growth with stalked glands, foetid, stems not armed Caesalpinea gilliesii

 

167 147 Leaves opposite 168


Leaves alternate 172

 

168 167 Trees; fruits samaras (dry, winged, indehiscent, one-seeded ) 169


Shrubs ( or occasionally small trees ); fruits not samaras 170

 

169 168 Leaflets barbellate on veins beneath, otherwise glabrous or nearly so Fraxinus uhdei


Leaflets not barbellate beneath, densely pubescent (in subspecies velutina) to glabrous (in supspecies glabra) Fraxinus pennsylvanica

 

170 168 Leaflets linear to narrowly lanceolate, coarsely serrate to dentate Tecoma stans


Leaflets broadly lanceolate to ovate 171

 

171 170 Leaflets ovate, to one inch ling, margins crenate to dentate; stems weak Tecomaria capensis


Leaflets ovate to broadly lanceolate, 2-4" long, margins serrate; stems upright Sambucus neomexicana

 

172 167 Leaves odd-pinnate (single leaflet at the apex of the leaf); if both even and odd pinnate leaves occur on same plant, use this choice 173


Leaves even-pinnate (paired leaflets at the apex of the leaf) 191

 

173 172 Upright tree like shrub with long, twining, vine-like branchlets, unarmed Wisteria sinensis

 Trees or shrubs, not with long, twining, vine-like branchlets, sometimes armed 174

 

174 173 Leaflet margins with 2-4 coarse basal teeth, each bearing a large gland beneath Ailanthus altissima


Leaflet margins dentate, serrate or entire, not toothed at base, not with glands beneath 175

 

175 174 Trees with graceful pendulous branchlets; leaflets 30 or more, linear-lanceolate, margins entire or often serrate, aromatic when crushed Schinus molle


Trees or shrubs with or without pendulous branchlets; leaflets 5-17, shapes various, sometimes aromatic when crushed 176

 

176 175 Leaflet margins serrate or dentate 177


Leaflet margins entire or undulate 182

 

177 176 Leaflets 5-11, lateral ones sessile 178


Leaflets 5-17, lateral ones short to long stalked 179

 

178 177 Leaflet margins coarsely dentate, dentations bristle-tipped; rachis not winged or margined Mahonia aquifolia


Leaflet margins serrate to dentate (sometimes entire), dentations or serrations not bristle-tipped; rachis winged or margined Schinus terebinthefolius

 

179 177 Leaflets usually 7-17, bases often inequilateral and midveins often curved; trees; stems and petioles not with prickles 180


Leaflets usually 5-7, bases sometimes inequilateral, midveins essentially straight; shrubs 181

 

180 179 Pith (soft tissue in center of stem) of branchlets chambered Juglans major

Pith of branchlets solid, not chambered Carya illinioensis

 

181 179 Stems and petioles with prickles; stipules large, fused to petiole most of their length, forming wings Rosa cathayensis


Stems and petioles rarely with prickles (if any); stipules minute, fused to petiole little of their length, not forming conspicuous wings Rosa banksiae

 

182 176 Plants with stipular spines (flwers white) Robinia pseudoacacia


Plants not with stipular spines 183

 

183 182 Leaflets and branchlets glabrous or nearly so 184


Leaflets and branchlets obviously pubescent 188

 

184 183 Leaflets distinctly alternate, glandular dotted Murraya paniculata


Leaflets opposite or subopposite, not glandular 185

 

185 184 Shrubs; branches angled or slightly winged Jasminum humile

Trees; branches terete; leaves sometimes even-pinnate 186

 

186 185 Leaflets 5-7, aromatic when crushed Schinus terebinthefolius


Leaflets 9-13, not aromatic when  crushed 187

 

187 186 Leaflets lanceolate, obtuse Pistacia terebinthus

Leaflets lanceolate, acuminate Pistacia chinensis

 

188 183 Shrubs or small trees; at least the terminal leaflets obovate to oblanceolate 189


Trees; leaflets oblong-ovate to lanceolate 190

 

189 188 Terminal leaflets to 1/2" long, mucronate Osteomeles schweriniae


Terminal leaflets 1" or more long, emarginate Sophora secundiflora

 

190 188 Leaflets broad ovate, long apiculate Dalbergia sissoo


Leaflets lanceolate to oval, obtuse to acute Sophora japonica

 

191 172 Trees; leaflets broadly oval to orbicular, to 1" or more wide Ceratonia siliqua


Trees or shrubs; leaflets obovate, ovate to linear, or if orbicular, then less than 1/4" wide 192

 

192 191 Leaves often of two types or dimorphic (once pinnate and twice pinnate leaves on the same tree); trees to 150' tall, with spreading branches; trunk with large, stout, simple or branched thorns Gleditsia triacanthos


Leaves not dimorphic; trees or shrubs to 40' tall 193

 

193 192 Trees; leaflets acuminate, often sickle shaped (falcate), distinctly inequilateral Pistacia chinensis


Trees or shrubs; leaflets not acuminate, not falcate, equilateral or not 194

 

194 193 Petiole with a gland between lowest leaflets; plants not armed 195


Petiole not with glands; plants sometimes armed 197

 

195 194 Leaflets linear, nearly terete, gray tomentose throughout Senna artemisioides


Leaflets oblong to ovate-lanceolate or obovate, green above, lighter green beneath, glabrous to pubescent, but not tomentose 196

 

196 195 Leaflets 3-6 pairs, obovate (to oblong), sparingly pubescent, long pubescent on midveins beneath, Senna splendida


Leaflets 2-3 pairs, oblong to ovate or lanceolate, glabrous Senna corymbosa

 

197 194 Plants with stipular spines, paired and slightly recurved; leaflets about 1/2" long Olneya tesota


Plants not with stipular spines; leaflets 1 or more inches long 197a

 

197a 197 Leaflets 2-7" long Cassia alata

Leaflets about 1" long Cassia didymobotrya

 

198 140 Trunk with large white prickles at base Chorisia speciosa


Trunk not armed 199

 

199 198 Leaves opposite; leaflets dark green above, grayish tomentose beneath; old inflorescences persistent, flowers blue Vitex agnus-castus


Leaves alternate; leaflets never grayish tomentose beneath; inflorescence not persistent 200

 

200 199 Leaflets to 12" long, 5" wide, glabrous, margins entire Schefflera digitata


Leaflets to 6" long, to 2" wide, glabrous or pubescent, margins finely to coarsely dentate 201

 

201 200 Trees; leaflets pubescent, to 2" wide; margins finely dentate (denticulate) to subentire, petioles not blotched Casimiroa edulis


Shrubs; leaflets glabrous, to 1" side; margins coarsely dentate, petioles blotched Dizygotheca elegantissima

 

  Leaves simple Section 8AA
   Leaves whorled or opposite Section 8B

 

202 135 Leaves whorled or opposite (occasionally nodes with whorled, supopposite or even alternate leaves) 203


Leaves alternate (at least in upper portions of plant) 245

 

203 202 Leaves whorled, 3 leaves or more per node 204


Leaves opposite 207

 

204 203 Leaf blades broad ovate, 3" or more wide Catalpa bignonioides


Leaf blades linear to lanceolate, to 1" wide 205

 

205 204 Leaves elliptic to lanceolate to ovate, with a medicinal odor when bruised Myrtus communis


Leaves linear, not with a medicinal odor when bruised 206

 

206 205 Leaves rigid, upright on stem Nerium oleander


Leaves not noticeable thickened, drooping from stem Chilopsis linearis

 

207 203 Plants parasitic (but green), growing on branches of ash, willow or cottonwood trees Phoradendron flavescens


Plants not parasitic, not growing on branches of trees 208

 

208 207 Leaf blades mostly linear or narrowly lanceolate or oblanceolate, at least 3 times longer than wide 209


Leaf blades mostly not 3 times longer than wide 214

 

209 208 Plants low or trailing shrubs, strongly aromatic when bruised; leaf blades linear, margins revolute (nearly tubular) Rosmarinus officinalis


Plants upright, not strongly aromatic when bruised; leaf margins not strongly revolute 210

 

210 209 Leaves dark green above, lighter colored and tomentose or peltate scaled beneath 211


Leaves green on both surfaces, glabrous or nearly so 212

 

211 210 Trees; leaf blades to 3" long, thick, peltate scaled beneath; margins entire, slightly rolled under Olea europaea


Shrubs; leaf blades to 6" or more long, thin, tomentose beneath; margins serrate Buddleja davidii

 

212 210 Trees or shrubs (woody throughout except for current year's growth) to 5' or more feet tall 213


Suffrutescent herbs (woody only at base) to 3' tall Ruellia brittoniana

distinguish between, lavender, white and pink

 

213 212 Leaf blades mostly 4" or more long; leaves often opposite, whorled and alternate on same branch, drooping from stem. Chilopsis linearis


Leaf blades mostly less than 3" long; leaves all opposite, not drooping (dwarf plant with narrow leaves is cv. 'Nana') Punica granatum

 

214 208 Plants with milky sap, with dichotomously branching (bifurcate) thorns or thornless Carissa grandiflora


Plants not with milky sap, not with bifurcate thorns 215

 

215 214 At least some leaves with margins variously dentate, serrate, crenate or lobed, but not entire. 216


Leaf margins entire or undulate 225

 

216 215 Leaf margins deeply lobed (laciniate) to entire, not regularly serate, crenate or dentate. Syringa laciniata


Leaf margins regularly serrate, crenate or dentate, sometimes remotely so, but not lobed 217

 

217 216 Leaf blades very rough pubescent (strigose-scabrous) 218


Leaf blades not strigose-scabrous. 219

 

218 217 Leaf blades mostly 2-3 inches long; plants upright; older stems sometimes with prickles Lantana camara


Leaf blades mostly 1" long; plants trailing; stems not armed Lantana montevidensis

 distinguish between purple, white and monrovia multicolored form

 

219 217 Herbage stellate pubescent, at least when young, sometimes sparingly so 220


Herbage not stellate pubescent 221

 

220 219 Leaves acuminate, cuneate; margins coarsely crenate-serrate, tips of serrations not directed forward; petioles long, not deeply channelled above Callicarpa bodinieri var. giraldii


Leaves obtuse to acute, rounded to broadly cuneate; margins finely crenate-serrate, tips of serrations directed forward; petioles short, deeply channelled above Viburnum suspensum

 

221 219 Leaves foetid, broadly feltoid-ovate, truncate; margins coarsely dentate; petioles 1/2 to as long as blade Clerodendrum bungei


Leaves not foetid, not broadly deltoid-ovate, cuneate or rounded at base; margins finely serrate to crenate; petioles less than 1/3 length of blade 222

 

222 221 Branchlets bearing stipular ridges between opposing leaves; leaves obtuse to acute to acuminate, sometimes fleshyp; serrations not bristle-tipped 223


Branchlets not bearing stipular ridges; leaves obtuse, fleshy; serrations minutely rolled under or thickened, minutely bristle-tipped

cv. 'Albo marginata' has leaves with green centers and irregular white margins 'Viridi-variegatus has leaves with cream centers and irregular green margins, leaves less than 1" long in cv. 'Microphylla' Euonymus japonica

 

223 222 Branchlets glabrous; leaves thick, fleshy, mostly about 2" or more long 224


Branchlets pubescent; leaves thin, not fleshy, mostly about 1" long Abelia x grandiflora

 

224 223 Leaves obtuse; margins with a few remote teeth (sometimes entire); buds obtuse Viburnum japonicum


Leaves acute to acuminate; margins with many rather close-set teeth; buds acute Osmanthus fragrans

 

225 215 Shrubs or small trees, succulent; branches brittle; leaves glabrous, very fleshy, obovate to 1" long Portulacaria afra


Shrubs or small trees, not succulent; branches not brittle; leaves glabrous or pubescent, not very fleshy, shapes and sizes various 226

 

226 225 Leaves with a strong medicinal odor when bruised 227

Leaves not with a strong medicinal odor when bruised 228

 

227 226 Leaves ovate to elliptic, longer than wide, bases not overlapping about stem (type with leaves partially folded, crowded on stem, lower ones deflexed is cv. 'Boetica' ; dwarf form with small, flat leaves is cv. 'Compacta'  Myrtus communis


Leaves very broadly ovate, often wider or as wide as long, bases overlapping about the stem (mature leaf form much longer, hence plants are pruned back to maintain juvenile leaf form) Eucalyptus pulverulanta

 

228 226 Branchlets and leaves (at least on midveins beneath) pubescent 229


Leaves glabrous 238

 

229 228 Midveins appearing as white stripes on green surfaces beneath; leaf blades to 1" long 230


Midveins not appearing as white stripes on green surfaces beneath; leaf blades often more than 1" long 231

 

230 229 Leaves obovate, obtuse or emarginate Buxus microphylla


Leaves ovate to elliptic, not obovate, acute Buxus sempervirens

 

231 229 Lower leaf surfaces pubescent throughout (sometimes sparingly so) 232


Lower leaf surfaces pubescent only along veins (and sometimes margins) 237

 

232 231 Leaves felty beneath with dense white tomentum 233


Leaves not felty beneath 234

 

233 232 Stem squarish and minutely ridged longitudinally along angles; stipular ridge between opposing leaves present; lateral veins sharply directed forward forming about 30 degree angles with midvein Teucrium fruticans


Stem terete, not ridged longitudinally; no stipular ridge; lateral veins less sharply directed forward, forming 34-60 degree angles with midvein Feijoa sellowiana

 

234 232 Leaves sessile or very short-petioled Simmondsia chinensis


Leaves distinctly petioled 235

 

235 234 Leaves distinctly oblanceolate, short apiculate Duranta stenostachya


Leaves ovate to elliptic 235a

 

235a 235 Leaves acuminate to apiculate; flowers blue Eranthemum pulchellum

Leaves obtuse to acute; flowers red, orange or white 235b

 

235b 235a Petioles long, at least one-fourth length of leaf; flowers with in dense clusters, each flower with a large red-brown barck justicia brandegeana

Petioles short, less than one-fourth length of leaf; flowers red or orange, in open clusters, bracts in conspicuous or absent 236

 

236 235b Leaves broadly ovate; flowers red, in elongate unbranched clusters Justicia californica


Leaves elliptic; flowers orange, in short branching clusters Jacobinia hybr.

 

237 231 Leaves long-petioles; lateral veins with tufts of hairs in axils; pubescence often partly stellate Viburnum tinus


Leaves short-petioled or sessile; lateral veins sometimes pubescent, not stellate Lagerstroemia indica

 

238 228 Branches ending in two lateral buds, terminal bud aborting Syringa x persica


Branches ending in one functional terminal bud 239

 

239 238 Leaves narrowly elliptic to often oblanceolate, not with obvious waxy coating; branchlets margined or winged, sometimes spinescent Punica granatum


Leaves broadly elliptic to ovate, not oblanceolate, usually with obvioius waxy coating; branchlets not margined, not winged, not spinescent 240

 

240 239 Branchlets obviously pubescent; some leaves usually alternate, deflexed Polygala dalmaisiana


Branchlets glabrous or nearly so; leaves opposite 241

 

241 240 Lenticels present on branchlets; stipules not large and sheathing; veins not impressed (sunken) above 242


Lenticels not present on branchlets; stipules large, sheathing; veins impressed (sunken) above Gardenia jasminoides

 

242 241 Bud scales stellate pubescent Viburnum japonicum


Bud scales glabrous or with very short simple hairs 243

 

243 242 Leaf blades elliptic, ovate or oblong, 1 to 2 1/2" long, acute, cuneate (leaf margins variegated with yellow in cv. 'Aureum') Ligustrum ovalifolium


Leaf blades rounded ovate to ovate-lanceolate, 2-6" long, obtuse, acute, or acuminate, rounded or tapering at base 244

 

244 243 Leaf blades 4-6" long, long acuminate; shrubs or shall trees to 30' tall Ligustrum lucidum


Leaf blades 2-4" long, short acuminate to obtuse; shrubs to 10' tall Ligustrum japonicum

 

    Leaves alternate Section 8BB
     Plants armed with thorns, spines or prickles Section 8C

 

245 202 Stems armed with spines, thorns or thorn-like branches 246


Stems not armed 265

 

246 245 Petiole winged or margined, jointed at base of blade; Citrus (best distinguished by fruits; many hybrids known; thorniess and leaf margins variable) 247


Petiole neither winged or margined, not jointed at base of blade 253

 

247 246 Fruit ovoid, sometimes nippled at apex 248


Fruit spherical or apically depressed, not nippled 250

 

248 247 Petiole narrowly winged; fruit sometimes nippled, greenish yellow to orange when ripe 249


Petiole margined; fruit nippled, yellow when ripe Citrus lemon

 

249 248 Small trees or shrubs, usually thornless; fruit sometimes nippled, flesh greenish Citrus aurantiifolia


Small trees, often thorny; fruit not nippled, flesh orange-yellow Fortunella margarita

 

250 247 Fruit 3' or more in diameter, skin tight; fruit segments inside not readily separable 251


Fruit 2-3" in diameter, skin loose; fruit segments inside readily separable Citrus reticulata

 

251 250 Skin of fruit warty, orange; fruit sour Citrus aurantium


Skin of fruit smooth, yellow or orange; fruit sweet to sour 252

 

252 251 Fruits 4" or more in diameter, yellow, sour Citrus paradisi


Fruits about 3" in diameter, orange, sweet Citrus sinensis

 

253 246 Shrubs; leaves and stems bearing peltate scales; blades silvery below, speckled brown Eleagnus pungens


Trees or shrubs; leaves and stem not bearing peltate scales 254

 

254 253 Vein pattern palmate; leaves arranged on slender branches giving the appearance of being pinnately compound Zizyphus jujuba


Vein pattern pinnate or palmate; leaves not appearing as being compound 255

 

255 254 Stems bearing spines (modified leaf structures) 256


Stems bearing thorns (modified stems) 259

 

256 255 Spines are modified bracts along main axes; leaves (actually modified stems called cladodes) fascicled 257


Spines are modified persistent petioles (with buds at base, in axils) 258

 

257 256 Cladodes about 1" long, straight or nearly so, margins not noticeable crisped Asparagus densiflorus v. sprengeri


Cladodes bout 2-3" long, often sickle-shaped (falcate), margins often noticeable crisped Asparagus falcatus

 

258 256 Plant branching near its base into many wand-like stems bearing greenish stripes or patches Fouquieria splendens


Plant with large whitish inverted carrot-shaped trunk, bearing lateral branches throughout; not with greenish stripes or patches Idria columnaris

 

259 255 Trees; leaves ovate, long acuminate or apiculate 260


Shrubs, sometimes vine-like; leaves various 261

 

260 259 Trees with milky sap; leaf margins entire or ciliate Maclura pomifera


Trees not with milky sap; leaf margins serrate Pyrus kawakami

 

261 259 Leaf blades obovate to oblanceolate, widest above the middle 262


Leaf blades ovate to lanceolate, widest below the middle 263

 

262 261 Leaves fleshy, obtuse, not emarginate, not stipulate; margins entire Lycium exsertum


Leaves not fleshy, usually emarginate, stipulate; margins irregularly serrate to entire Pyracantha fortuneana

 

263 261 Shrubs with vine-like branches; leaves entire, apiculate Bougainvillea spectabilis


Shrubs not with vine-like branches; leaves serrate, crenate or sometimes entire, not apiculate 264

 

264 263 Leaves 2" or more long; stipules (when present) large, broad and leaf-like Chaenomeles japonica


Leaves mostly to 1" long; exstipulate Condalia lycioides

 

      Plants unarmed Section 8CC
       Margins lobed, serrate, dentate, etc. Section 8D

 

265 245 Leaf margins lobed, serrate, dentate or crenate, but neither entire nor undulate 266


Leaf margins entire or undulate (wavy) 328

 

266 265 Leaf margins distinctly lobed (at least in some leaves) 267


Leaf margins serrate, dentate or crenate, not distinctly lobed 290

 

267 266 Leaf margin two-lobed (bilobed) 268


Leaf margin not bilobed 270

 

268 267 Shrubs; leaves small, viscid; lobes pointed, midvein prolonged slightly between them Larrea divaricata


Trees; leaves larger, not viscid; lobes rounded, not evident midvein 269

 

269 268 Vein pattern dichotomous; internodes of some branches markedly shortened Ginkgo biloba

 
Vein pattern palmate; internodes not markedly differentiated (flowers purple; white flowered variety is candida) Bauhinia variegata

 

270 267 Primary lobes and vein pattern of leaf pinnate 271


Primary lobes and vein pattern of leaf palmate 278

 

271 270 Shrubs; semi-succulent; leaf blades large to 3' long, deeply secondarily lobed Philodendron selloum


Trees or shrubs; sometimes semi-succulent; leaf blades less than 2' long 272

 

272 271 Trees to 150' tall; leaf blades 10" long or more long, with secondary lobes entire or again lobed, silky beneath; margins revolute Grevillea robusta


Trees or shrubs to 60' tall; leaf blades usually less than 8" long, not with secondary lobes, not silky beneath; margins not revolute 273

 

273 272 Trees or shrubs to 60' tall, with slender drooping branchlets 274


Small trees or shrubs to 15' tall, with upright branches or unbranched 276

 

274 273 Leaf blades rhombic (diamond-shaped), bearing a few lobes; branches drooping Pittosporum rhombifolium


Leaf blades not rhombic; branches sometimes drooping 275

 

275 274 Trees; leaves ovate with long acuminate tips; unlobed or with 1-5 shallow lobes Brachychiton populneum  


Shrubs; at least some leaf margins deeply 3-7 lobed Syringa laciniata

 

276 273 Plants semi-succulent; stems wand-like with milky sap; leaves not rigid Euphorbia pulcherrima


Plants not succulent; stems neither wand-like nor with milky sap 277

 

277 276 At least some leaves lyrate-pinnatifid; sprawling shrubs; bark peeling Oenothera speciosa var. childsii


Leaves rectangular, bearing a few lobes with stout spines, not lyrate-pinnatifid; upright shrubs; bark not peeling (margins little lobed to entire in cv. 'Burfordii') Ilex cornuta

 

278 270 Primary lobes (and secondary lobes if present) with entire, lobed or undulate margins 279


Primary lobes (and secondary lobes if present) with crenate, serrate or dentate margins 283

 

279 278 Suffrutescent herbs, vines or low shrubs to 12' or sometimes more if vine-like 279a


Trees to 60'; leaves various 280

 

279a 279 Leavs leathery, with 3-5 shallow lobes Fatshedera lizei

Leaves not leathery, more than 5-lobed Tetrapanax papyrifera

 

280 279 Large trees with bark peeling in large flakes; petiole covering the bud Platanus wrightii


Trees, not with bark peeling in large flakes; petiole not covering the bud 281

 

281 280 Trees with drooping branches; leaves ovate with long acuminate tips and unlobed or with 1-5 lobes Brachychiton populneum


Trees, not with drooping branches; leaves ovate-orbicular with 3-5 digitate lobes, not long acuminate 282

 

282 281 Leaves glabrous (except for a few scattered stellate hairs on veins); lobes obtuse Brachychiton acerifolium


Leaves with stellate hairs, at least beneath; lobes acute Firmiana platanifolia

 

283 278 Leaves peltate Ricinus communis


Leaves not peltate 284

 

284 283 Large trees with bark peeling in large flakes; petiole covering the bud Platanus x acerifolia


Trees or shrubs, not with bark peeling in large flakes; petiole not covering the bud 285

 

285 284 Upper surfaces of leaf blades distinctly very scabrous 286


Upper surfaces pubescent or glabrous, but not distinctly very scabrous 287

 

286 285 Stipular ring scars present (sometimes incomplete rings); stems with abundant milky sap Ficus carica


Stipular ring scars not present; stems not with abundant milky sap Broussonetia papyrifera

 

287 285 Trees to 50'; leaf margins unlobed or regularly to irregularly lobed (common form is cv. Mapleleaf; small leaved weeping form cv. Pendula


Shrubs to 15' tall; leaf margins usually lobed 288

 

288 287 Leaves glabrous; primary lobes 5-9 Fatsia japonica


Leaves with at least a few stellate hairs (sometimes simple hairs also); primary lobes usually 3 289

 

289 288 Leaves tomentose, margins shallowly 3-lobed, bases cordate to truncate; petioles about as long as blade Malvaviscus arboreus


Leaves nearly glabrous, margins shallowly to deeply 3-lobed, these often secondarily lobed, bases cuneate; petioles less than 1/2 length of blade Hibiscus syriacus

 

290 266 Prostrate subshrubs to about 1' tall; leaves oblanceolate to obovate 291


Trees or shrubs; leaves various 292

 

291 290 Leaves and stems bumpy glandular, blades narrowly lanceolate Myoporum parvifolium


Leaves and stems not bumpy glandular, blades broadly oblanceolatre to obovate, scurfy Baccharis pilularis

 

292 290 Stems with abundant milky sap 293


Stems not with abundant milky sap 294

 

293 292 Stipular ring scars present; leaves ovate-orbicular, margins coarsely dentate Ficus roxburgii


Stipular ring scars not present; leaves elliptic to ovate; margins irregularly few-toothed Euphorbia pulcherrima

 

294 292 Leaves (actually phyllodes) triangular to 1" long, midvein strongly curved with mucro at apex forming one angle of triangle, one lateral glandular tooth forming another angle Acacia cultiformis


Leaves not triangular as described above, lengths various 295

 

295 294 Petioles winged or margined, jointed at base of blade; blade glandular dotted, irregularly serrate or crenate to entire; Citrus(best distinguished by fruits, many hybrids known; see Key Number 247ff for additional species) 296


Petioles not winged or margined, not jointed at base of blade; blade not glandular dotted; regularly to irregularly serrate, crenate or dentate 297

 

296 295 Trees to 2-' tall; fruit spherical, smooth-skinned, orange, to 3" long, with many compartments (locules) inside Citrus sinensis


Shrubs or small trees to 12' tall; fruit ovoid, 1 to 1 1/2" long with 4-5 locules Fortunella margarita

 

297 295 Trees; leaf bases usually distinctly inequilateral 298


Trees or shrubs; leaf bases equilateral or nearly so 300

 

298 297 Leaf margins doubly serrate Ulmus americana


Leaf margins simply serrate 299

 

299 298 Leaves ovate-oblong, long acuminate; trunks gray, smooth or with warty protuberances Celtis occidentalis


Leaves elliptic-ovate, acute; trunks dark, furrowed at maturity Ulmus parvifolia

 

300 297 Leaves rhombic (diamone-shaped); dentations coarse, irregular 301


Leaves not rhombic; dentations or serrations various 302

 

301 300 Leaves and branchlets covered with mealy silvery gray scales Atriplex lentiformis ssp. breweri


Leaves and branchlets glabrous, not with mealy scales Pittosporum rhombifolium

 

302 300 Leaf blades broadest at or below the middle, lanceolate, ovate, deltoid, ovate-orbicular, oval or elliptic (often some leaves broadest above the middle, rarely consistently so) 303


Leaf blades prevailingly broadest above the middle-oblanceolate or obovate 322

 

303 302 Serrations or dentations spinescent 304


Serrations or dentations or crenations not spinescent, but sometimes with very minute bristles 309

 

304 303 Large trees; leaves tomentose (at least beneath), pubescence stellate in part 305


Shrubs or small trees; glabrous to tomentose, but not stellate 306

 

305 304 Bark much corky, deeply furrowed at maturity leaf margin regularly dentate Quercus suber


Bark not corky, smooth at maturity; leaf margin with few dentations to nearly entire Quercus ilex

 

306 304 Leaf margins regularly serrate or dentate; leaves and branchlets bearing some pubescence; leaves elongate 307


Leaf margins irregularly serrate to entire; leaves and branchlets glabrous; leaf shapes various 308

 

307 306 Leaves whitish tomentose beneath sometimes becoming glabrate, distinctly cuneate at base Vauquelinia californica


Leaves tan or brown pubescent beneath sometimes becoming glabrate, bases rounded to broadly cuneate Heteromeles arbutifolia

 

308 306 Shrubs; dentations bearing stout spine tips; leaves very thick, rigid Ilex x altaclarensis 'Wilsoni'


Small trees; dentations spinescent, but not bearing stout spine tips; leaves thick, a little flexible Prunus caroliniana

 

309 303 Petioles bearing glands at base of blade 301


Petioles not bearing glands 311

 

310 309 Leaves broadly ovate, apiculate Prunus armeniaca


Leaves narrowly lanceolate, acuminate Prunus persica

 

311 309 Leaves obviously pubescent, well distributed 312


Leaves glabrous or very nearly so 314

 

312 311 Trees or shrubs; leaf blades palmately veined 313


Trees; leaf blades pinnately veined 312a , not broad ovate, to 3" long, finely serrate

 

312a 312 Leaf margins serrate Malus sylvestris

Leaf margins coarsely dentate or crenate Populus alba

 

313 312 Trees; leaves not stellate pubescent 313a


Shrubs; leaves sparsely stellate pubescent; petiole not channelled above Hibiscus rosa-sinensis

 

313a 313 Leaves densely white tomentose beneath Populus alba

Leaves not tomentose beneath (common form is  cv. 'Maple Leaf'; small leaved, weeping form is cv. 'Pendula' Morus Alba Morus alba

 

314 311 Trees; leaves narrowly lanceolate to linear 314a


Trees or shrubs; leaves broadly ovate to elliptic, not narrowly lanceolate or linear 316

 

314a 314 Leaves and branches variously twisted and contorted (cv. Tortuosa) Salix matsudana

Leaves and branches not twisted or contorted 315

 

315 314a Branches distinctly pendulous Salix babylonica


Branches not distinctly pendulous Salix gooddingii var. variabilis

 

316 314 Leaves broadly deltoid-ovate; coarsely crenate-dentate, tips often incurved; petiole flattened laterally Populus fremontii


Leaves not broadly deltoid-ovate; petiole not flattened laterally 317

 

317 316 Leaf blades obtuse, about 1" long, margins serrate-crenate, crenations tipped with minute bristles Ilex vomitoria


Leaf blades acute to acuminate; mostly 1 1/2" or more long; serrations sometimes minutely bristled 318

 

318 317 Leaves purple Prunus cerasifera 'Atropurpurea'


Leaves green 319

 

319 318 Trees; leaf tips apiculate, abruptly narrowed into a prominent point 320


Shrubs; leaf tips acuminate, not abruptly narrowed to a point 321

 

320 319 Leaves deciduous; petioles naked Pyrus communis


Leaves evergreen; petioles usually bearing a few serrations extending down from blade Pyrus kawakamii

 

321 319 Marginal serrations usually bearing minute yellow callosites, not minute bristles Xylosma congestum


Marginal serrations bearing minute bristles, not callosities Camellia japonica

 

322 302 Shrubs; leaves definitely obovate; serrations, crenations or dentations mostly restricted to upper half of blade 323


Trees or shrubs; leaves oblanceolate; serrations, crenations or dentations to well below the middle of the leaf blade 325

 

323 322 Branches pendulous; leaf blades thin, less than 1" long Spiraea x vanhouttei


Branches not pendulous; leaf blades thick, lengths various 324

 

324 323 Leaf blades less than 1" long, glandular dotted Myrsine africana


Leaf blades mostly 1 1/2" or more long, not glandular dotted (R. indica Lindl. and intermediate hybrid, R. x delacourii, have sharper dentations and pink flowers, not white as in R. umbellate) Raphiolepis umbellata

 

325 322 Leaf blades tawny to rusty tomentose beneath, 5-10 inches long Eriobotrya japonica


Leaf blades glabrous or glabrate, not tomentose, 2-6" long 326

 

326 325 Leaf apex mucronate; younger branchlets pubescent or glabrous, not stipitate glands, stipulate 327


Leaf apex not mucronate; younger branchlets often hirsute or with stipitate glands; exstipulate Arbutus unedo

 

327 326 Leaf blades elliptic-oblanceolate, usually reddish beneath when immature; stamens 10, persisting on fruit Heteromeles arbutifolia


Leaf blades oblong-oblanceolate, greenish beneath when immature; stamens 20, persisting on fruit (serrations spinescent in cv. Aculeata) Photinia serrulata

 

       Margins entire or undulate Section 8DD

 

328 265 Petioles succulent, ensheathing stem; leaf blades 1-5 feet or more long; stem unbranched 329


Petioles sometimes succulent but not ensheathing stem; leaf blades usually less than 1' long; stems branching 332

 

329 328 Leaves arranged in two opposing rows along stem (two-ranked) 330


Leaves more than two-ranked 331

 

330 329 Leaf blades 2-5' long; false trunks 3' or more tall, of 3" or more in diameter Strelitzia nicolai


Leaf blades 12-18" long; trunkless or false trunk to 1' tall, of 1 1/2" or less in diameter Strelitzia reginae

 

331 329 Leaf blades 3-5 feet or more long, shredding in wind; plants appearing as small trees Musa nana


Leaf blades to 2' long, not shredding in wind; plants suffrutescent herbs, not appearing as small trees Canna generalis

 

332 328 Leaf blades leathery, with a medicinal or spice odor 333


Leaf blades sometimes leathery, not with a medicinal or spice odor 345

 

333 332 Leaf with spice odor (bay leaves), blades elliptic, 2-4" long Laurus nobilis


Leaf with medicinal odor; blades various 334

 

334 333 Clusters of sessile woody fruits persisting along stems 335


No Clusters of sessile woody fruits persisting along stems 339

 

335 334 Leaves about 1" or less long


Leaves about 1 1/2" or more long 337

 

336 335 Leaves tp 1/2" long, narrow, acuminate, inflorescence cylindric, 1-2" long Melaleuca pubescens


Leaves to 1" long, obovate, obtuse, mucronate; inflorescence a globose head about 1" long Melaleuca nesophyla

 

337 335 Small trees with pendulous branches Callistemon viminalis


Small trees or shrubs, not with pendulous branches 338

 

338 337 Leaves to 1/4" wide; new growth pubescent Callistemon rigidus


Leaves to 1/2" wide; new growth densely downy pubescent Callistemon citrinus

 

339 334 Trees; leaves petiolate, not crowded 340


Small trees or shrubs; leaves sessile or very short petiolate, usually crowded  339a

 

 

339a Myrtus communis

Leaves partially folded, crowded on stem, lower leaves deflexed or dwarf form with small flat leaves 339b

 

339b Dwarf form of 339a Myrtus communis 'Compacta'

Leaves partially folded, crowded on stem, lower leaves deflexed Myrtus communis 'Boetica'

 

340 339 Leaf blades narrowly lanceolate, mostly at least 4 times longer than wide, mostly broadest near the base and tapering to a long point 341


Leaf blades less than 3 times longer than wide 344

 

341 340 Bark of main branches smooth, peeling in plates 342


Bark of main branches rough, not peeling in thin plates 343

 

342 341 Bark and branchlets gray to brown; flowers whitish Eucalyptus camaldulensis


Bark whitish, branchlets bright reddish; flowers whitish to reddish Eucalyptus leucoxylon

 

343 341 Trees mostly to 20' tall; branchlets yellowish, little pendulous; fruits about 1/4" in diameter Eucalyptus torquata


Trees to 80' tall; branchlets reddish, pendulous; fruits about 1/8" in diameter Eucalyptus sideroxylon

 

344 340 Leaf blades nearly as wide to wider than long in juvenile leaf forms, more elongate in mature forms, silver gray, glaucous Eucalyptus polyanthemos


Leaf blades elliptic-ovate, reddish tinged when young turning greenish blue Eucalyptus rudis

 

345 332 Leaf blades linear, narrowly lanceolate or narrowly oblanceolate, mostly 4 or more times longer than wide 346


Leaf blades mostly less than 3 times longer than wide 358

 

346 345 Shrubs; stems green, wand-like or broom-like, longitudinally striate or winged 347


Trees or shrubs; stems not wand-like, not broom-like 348

 

347 346 Stems wand-like, finely striate; leaves elliptic, pubescent, not viscid-glandular Spartium junceum


Stems ascending, broom-like, winged; leaves linear, glabrous, viscid-glandular Baccharis sarothroides

 

348 346 Plants with milky sap Thevetia peruviana


Plants not with milky sap 349

 

349 348 Trees; leaf blades mostly to 1/2" long, linear, arranged on deciduous branchlets as to appear pinnately compound leaves Taxodium mucronatum


Trees or shrubs; leaf blades about 1" or more long, not arranged on branchlets as to appear as pinnately compound leaves 350

 

350 349 Leaf midvein extending beyond the blade, ending in a short apical hook; branchlets pendulous Pittosporum phillyraeoides


Leaf midvein not ending in an apical hook; branchlets pendulous or upright 351

 

351 350 Branchlets angled, pendulous; rachis of leaf expanded (phyllode), without leaflets and appearing as a linear leaf Acacia saligna


Branchlets not angled, pendulous or upright; leaf blade expanded 352

 

352 351 Leaves glabrous or nearly so 353


Leaves pubescent or scaly 357

 

353 352 Leaves drooping from branches; small trees 354


Leaves upright, not distinctly drooping; small trees or shrubs 355

 

354 353 Leaves leathery, alternate Geijera parviflora


Leaves not leathery, some nodes often with leaves opposite or in whorls of three Chilopsis linearis

 

355 353 Shrubs 355a


Small trees 356

 

355a 355 Leaves viscid-glandular blades flat (leaves purplish in cv. 'Purpurea') Dodonaea viscosa

Leaves not glandular, margins revolute, needle-like Grevillea noelii

 

356 355 Leaf blades mostly 1-2" long, 1/8" wide, acuminate, blue-glaucous Podocarpus gracilior


Leaf blades mostly 3-5" long, 1/3" or more wide, obtuse to acute, not blue-glaucous Podocarpus macrophylla

 

357 352 Low shrubs; leaves silvery canescent on both surfaces Convolvulus cneorum


Trees; leaves with peltate scales beneath, not canescent Olea europaea

 

358 345 Leaf blades acuminate, about 1" long, very rigid, waxy, midvein ending in a stiff spine Araucaria bidwillii


Leaf blades longer, or in about 1" long, then not spine-tipped 359

 

359 358 Leaf blades thin, bearing scattered silvery granules (at least beneath); with large leaf-like stipules Plumbago capensis


Leaf blades of various thicknesses, not bearing silvery granules, with or without granules 360

 

360 359 Trees with pendulous branches, trunks sometimes widening toward base at maturity; leaves long acuminate, often some margins lobed Brachychiton populneum


Trees or shrubs, if trees, not with pendulous branches; trunk not noticeably widening at base; leaves various, but not lobed 361

 

361 360 Small trees; leaves strongly cordate-orbicular, apiculate, palmately veined Cercis canadensis


Trees or shrubs; leaves not cordate-orbicular, shapes various, pinnately or palmately veined 362

 

362 361 Petioles winged or margined, jointed at blade; Citrus (best distinguished by fruits; many hybrids known; for additional species see Key Number 234ff) 363


Petioles if winged or margined not also jointed at blade 366

 

363 362 Shrubs or small trees to 12' tall; fruits ovoid, 1 to 1 1/2" long, with 4-5 compartments (locules) Fortunella margarita


Trees; fruits spherical or apically depressed, 2" or more long, with many locules 364

 

364 363 Skin of fruit warty, orange; fruit sour Citrus aurantium


Skin of fruit smooth, orange or yellow; fruit sweet to sour 365

 

365 364 Fruit 4" or more in diameter, yellow, sour Citrus paradisi


Fruit about 3" in diameter, orange, sweet Citrus sinensis

 

366 362 Plants with milky sap 367


Plants not with milky sap 370

 

367 366 Trees or shrubs; leaves leathery, shiny; stipular ring scars present 368


Suffrutescent herbs or weak-stemmed shrubs; leaves thin and dull, ovate, long-acuminate; stipular ring scars not present Ipomoea fistulosa

 

368 367 Leaf blades 2-5" long, blunt apiculate, not over 1 1/2" wide Ficus retusa


Leaf blades 8" or more long, long-acuminate or obtuse, more than three inches wide 369

 

369 368 Leaves elliptic (leaves less than twice as long as wide in cv. 'Decora') Ficus elastica


Leaves lyrate Ficus pandurata

 

370 366 Stipular ring scars present; leaf blades long-ovate, thick, shiny, to 10 or more inches long Magnolia grandiflora


Stipular ring scars not present; leav blades less than 8" long 371

 

371 370 Leaf blades strongly 3-veined beneath, oblong-lanceolate to elliptic, 2-5" long, acute to acuminate, cuneate, glabrous or very nearly so Cocculus laurifolius


Leaf blades not strongly 3 veined beneath; leaf shapes and sizes various, glabrous or pubescent 372

 

372 371 Branchlets strongly angled, winged or ridged longitudinally 373


Branchlets neither winged nor ridged longitudinally 375

 

373 372 Leaves sessile or very nearly so; leaves not usually cuneate-ovate Lagerstroemia indica


Leaves distinctly petioled; leaves of various shapes, cuneate 374

 

374 373 Leaves pubescent, with forked hairs; branchlets regularly ridged or winged Solanum rantonnetii


Leaves glabrous or sparsely pubescent with simple hairs; branchlets angled, flattened on upper surface between angles Capsicum frutescens

 

375 372 Leaves with peltate scales beneath 376


Leaves not with peltate scales 378

 

376 375 Shrubs; leaves broad ovate, scales mixed silvery speckled with brown Eleagnus pungens


Trees; leaves ovate to elliptic, scales silvery 377

 

377 376 Trunks not noticeable gnarled; leaves ovate, obtuse, not mucronate Lagunaria pattersonii


Base of trunks much gnarled at maturity; leaves linear to narrowly elliptic, acute, sharp mucronate Olea europaea

 

378 375 Leaves sparingly pubescent or glabrous 379


Leaves tomentose or lanate, at least beneath 390

 

379 378 Young branchlets obviously pubescent 380


Young branchlets glabrous or nearly so 385

 

380 379 Leaves prevailingly oblanceolate, crowded near tips of branches  380a


Leaves not prevailingly oblanceolate, well-distributed along branchlets 381

 

380a  Pittosporum tobira

         Pittosporum tobira 'Wheeler's Dwarf'

 

380b Pittosporum tobira 'Variegata'

          Pittosporum tobira Dwarf Variegated

 

381 380 Leaves very broad ovate, not undulate 382


Leaves elliptic to lanceolate, undulate, not broad ovate 383

 

382 381 Trees; leaves large, 4" or more long Diospyros kaki


Shrubs; leaves small, to about 1" long Cotoneaster horizontalis

 

383 381 Blades rounded at base, sessile or nearly so, leaves sometimes opposite, deflexed Polygala dalmaisiana


Blades cuneate, petiolate or decurrent cuneate to base; leaves all alternate 384

 

384 383 Leaves thickish, leathery, deep green, shiny, 3-6" long; branchlets not stellate pubescent Pittosporum undulatum


Leaves thin, not leathery, grayish-green, not shiny, 2-4" long; branchlets stellate pubescent Solanum capsicastrum

 

385 379 Leaves blue-green, fleshy, glaucous, ovate and long-petiolate Nicotiana glauca


Leaves green, not fleshy, not glaucous, not long-petiolate 386

 

386 385 Leaves pale green, obovate to oblanceolate (sometimes oval); blades mostly about 1" long, thick (young leaves sometimes with a few small blackish remote teeth) Maytenus phyllanthoides


Leaves dark-green (at least above), neither obovate nor oblanceolate; blades 1 1/2" or more inches long, thicknesses various 387

 

387 386 Trees to 40'(sometimes pruned as shrubs); leaves with stipules, early deciduous but leaving scars; leaves thick stiff, sometimes serrate; branchlets dark Prunus caroliniana


Shrubs to 6' tall; leaves exstipulate, of various thicknesses, branchlets green 388

 

388 387 Leaves undulate, narrow Solanum pseudo-capsicum


Leaves not distinctly undulate, broad 389

 

389 388 Leaves acuminate, not short apiculate Cestrum parqui


Leaves acutish, bluntly short apiculate Brunfelsia calycina v. floribunda

 

390 378 Leaves densely white pubescent on both surfaces 391


Leaves greenish above, white tomentose beneath 392

 

391 390 Leaves ovate, long acuminate; branchlets brittle, often producing a resinous exudate Encelia farinosa


Leaves obovate, obtuse; branchlets not brittle, not producing an exudate Leucophyllum frutescens

 

392 390 Small tree; leaves ovate, large 2-8" long 393


Shrubs; leaves elliptic to narrowly ovate, small to 3" long, usually much less 394

 

393 392 Leaves glabrate above, not rough pubescent, stipulate Cydonia oblonga


Leaves rough pubescent above, exstipulate Cordia sebestena

 

394 392  Leaves with very short petioles; shrub to 2' tall Cotoneaster glaucophyllus


Leaves distinctly petiolate; shrubs to 3-4' or more tall 395

 

395 394 Leaves to 1" long, sparsely pubescent above; shrubs to 3' tall Cotoneaster pannosa


Leaves to 3" long, glabrate above; shrubs to 6' tall Cotoneaster parneyi

 

 

  

Key Words for Use in a Key

Abscission  Detachment of parts, such as leave from stems
Acicular    Needle shaped
Acuminate Tapering to a long point

 

Acute Pointed, sharp angled

  

Alternate Leaf arrangement, one leaf per node, spiraled
Apex(apical) Tip or top
Apiculate Abruptly narrowed to a point
Appressed Closely pressed against
Arborescent Tree like in form, usually with a distinct trunk at the base of the plant.

 Opuntia fulgida
Areoles Shortened pad like branches of cacti bearing leaves (usually as spines and or flowers) An organ common to the entire cacti family. Usually circular or oval, areoles are found along the stems of the plant. This areole is the structure from which spines grow, flowers will bud and new stems will branch.
Opuntia phaeacantha var. discata
Aristate
Armed Bearing spines, thorns or prickles
Ascending Habit
Auriculate
Axil(axillary) Angle formed by juncture of two structures, such as upper leaf surface and stem.
Barbellate Bearing small barbs or deflexed sharp projections.
Blade Flattened, expanded portion of the leaf, lamina
Bract Leaf modified in shape or color from the overall usual form on plant
Bristle-Like  
Bud

Stem tip with or without scales, leaves and/or flowers; located at branch apex or at base of leaf, in the axil.

Cespitose Growing in tufts or mats.
Callosity Hardened, often swollen protuberance
Canescent Gray pubescent, hoary
Chaffy Bearing thin, dry scales or bracts
Ciliate Bearing hairs or bristles along margin
Circinnate  
Cladode Flattened stem, appearing as a leaf
Clavate

Club shaped with a narrow base and swelling towards the top.

Opuntia fulgida

Cleft Leaf Margin
Compound Leaf

Bearing leaflets; Twice and Thrice compound leaves bearing leaflets subdivided into secondary leaflets or again sub divided into tertiary leaflets respectively.

Cordate Heart-shaped, rounded portions at base
Crenate  Scalloped margin; having rounded teeth
Crispate Leaf Margin
Culms  
Cuneate Wedge-shaped; tapering at base
 

Cuspidate

Deciduous Parts capable of detachment or abscission, usually seasonally, as opposed to evergreen
Decumbent Habit
Decurrent Referring to one structure fusing to another and extending downward, usually as lines or ridges
Deflexed  Directly backwards
Dehiscent Naturally splitting, usually along lines, in patterns
Deltoid Triangular in outline
Dentate Toothed, teeth usually directed outward,
Denticulate Margins have minute teeth
 
Dichotomous Forking, branches usually equally formed
 
Dimorphic

Having two distinct shapes

Dissected

Deeply cut or lobed

Double Serrate Leaf Margin
Elliptic  Having equal taper at tip and base, symmetrically flattened circle
Emarginate  Notched at apex
Ensheathing  
Entire  

Margin smooth, without indentations
 

Erose  
Exfoliate

To peel, often in plates or strips

Exudate  
Even Pinnate Compound
Exstipulate Without stipules
Falcate Sickle shaped; curved
Fascicle Cluster, bundle
Filament(filamentous) Threadlike structures
Filiferous Bearing filaments
Filiform Thread-like; extremely narrowed
Flexuous Pliable, easily bent
Floccose Tufts of soft hair
Foetid Malodorus, ill-smelling
Foliage(foliaceous) Collective term for leaves of a plant
Genus A genus is a group of organisms that are closely related and share similar characteristics
Glabrate  
Glaucous  
Globose  
Glochids  Fine hair like spines common in the areoles of many cacti. Glochids break away very easily and quickly become embedded in skin or clothing. These are common on cylindropuntia (cholla) and opuntia (prickly pear), but not found on other genuses.
Glochids
Hastate
Herbaceous  
Hirsute  
Imbricate Leaf Arrangement
Incised Leaf Margin
Indehiscent  
Inequilateral  
Inflorescence  
Internode  
Lacerate Leaf Margin
Laciniate Leaf Margin
Lanate  
Leaf Scars  
Linear
Lanceolate
Lobed Leaf Margin
Lyrate  
Midvein  
Mucronate
Needle-Like  
Oblanceolate
Obovate Oval or egg-shaped, with one end wider than the other.
 
Oblique  
Obtuse
Odd Pinnate Leaf
Opposite Leaf Arrangement
Orbicular  
Ovate
Palmate
Palmate Venation
Palmatifid Leaf Margin
Parallel Venation
Parted Leaf Margin
Peltate
Perfoliate Leaf Shape
Petiolate  
Petiole  
Pinnae  
Pinnate Venation
Pinnately Compound  
Bipinnately Compound
Tripinnately Compound
Pinnate Venation
Pinnatifid Leaf Margin
Perfoliate
Porrect  Extended horizontally.
Prickle  
Procumbent Habit
Pubescence  Covered with fine soft short hairs.
Rachis  
Reflexed  Turned backwards, bent or folding back.
Reniform Leaf
Repent Habit
Rhizomes  
Rosette  
Rounded
Reniform
Revolute  
Sagittate
Scale-Like  
Scapose  
Serrate Leaf Margin
Samara  
Serrulate Leaf Margin
Sessile  
Setaceous

 Set with bristles, bristle-like

Simple Leaf
Spathulate

Spines

 
Spinescent  
Stalked  
Stellate Hairs  
Stipular Ridge  
Stipular Scar  
Stipulate  
Stipules  
Succulent  A plant that stores water in fleshy leaves or stems
Subulate
Suffrutescent  
Striate  Marked with longintudinal lines, grooves or ridges.
Tendrils  
Terete  
Tomentose  
Truncate  Blunt or square at the tip, as if cut off.
Tuber   A large root or underground stem that is used to store water and nutients for the plant.
Tubercles A raised protruberance on the stem of the plant, usually surrounding each areole.
Turgid  Swelled or distended as by some internal pressure.
Umbilicate apex

A depressed and scarred center indicating where the flower was attached to the top of the fruit

Undulate Leaf Margin
Variety  A sub division of a species
Viscid Glandular  
Whorled Leaf Arrangement

  

Key to the Yuccas

 

1 Fruits indehiscent, pendent or occasionally erect. (2)

+ Fruits dehiscent, erect. (9)

 

2 (1) Fruits dry and spongy or leathery. (3)

+ Fruits fleshy and succulent. (4)

 

3 (2) Leaf blade 15–35 Χ 0.7–1.5 cm, rigid; fruits 6–8.5 cm; sw United States. 1 Yucca brevifolia

+ Leaf blade 40–100 Χ 3.5–6 cm, rigid or flexible; fruits 2.5–8 cm; se United States. 8 Yucca gloriosa

 

4 (2) Tepals connate basally for 1 mm or more; pistil 2.8–8 cm. (5)

+ Tepals distinct, or connate basally for less than 1 mm; pistil 1.5–4 cm. (6)

 

5 (4) Mature plants taller than 2.5 m; tepals 3.9–10.8 cm. 2 Yucca faxoniana

+ Mature plants shorter than 2.5 m; tepals 4.5–13 cm. 3 Yucca baccata

 

6 (4) Leaf blade thin, flexible, margins entire or occasionally filiferous with slender fibers. 4 Yucca madrensis

+ Leaf blade thick, rigid, margins entire, denticulate, or filiferous with slender or coarse fibers. (7)

 

7 (6) Leaf margins sharply denticulate or entire, rarely filiferous with slender fibers. 7 Yucca aloifolia

+ Leaf margins entire, filiferous with coarse fibers. (8)

 

8 (7) Style 2–8 mm. 5 Yucca treculeana

+ Style 1–2 mm. 6 Yucca schidigera

 

9 (1) Leaf margins entire or often denticulate, sometimes wavy, lemon yellow to orangish red or reddish brown; pistil 2.5–4.5 cm. (10)

+ Leaf margins entire, filiferous or becoming so, not wavy, whitish to gray, light green, or light brown; pistil 1.5–3.8 cm. (14)

 

10 (9) Mature plants caulescent; rosettes each with more than 100 leaves. (11)

+ Mature plants acaulescent, usually forming colonies; rosettes each with fewer than 100 leaves. (12)

 

11 (10) Mature plants 2.5–3.6 m, not including inflorescence; leaf blade 25–60 Χ 1.2–1.7 cm, widest considerably above middle, smooth. 9 Yucca rostrata

+ Mature plants 0.7–2.5 m, not including inflorescence; leaf blade 20–30(–45) Χ 0.7–1.2 cm, widest at or above middle, ± scabrous. 10 Yucca thompsoniana

 

12 (10) Plants in colonies of 10–30 rosettes each; mature leaf blade straight, flat except becoming concave near apex, glaucous, margins wavy, yellow; inflorescences with wide-spreading branchlets. 11 Yucca pallida

+ Plants in open colonies of 2–15 rosettes each, or sometimes solitary; leaf blade flattened or twisted and concave, glaucous or not, margins yellow, dark orange, or reddish brown; inflorescences narrowly ovoid. (13)

 

13 (12) Mature leaf blade twisted, strongly concave, 1.7–4 cm at greatest width, flexible, margins orange or reddish brown. 12 Yucca rupicola

+ Mature leaf blade straight, slightly concave, 1–2(–2.5) cm at greatest width, rigid, margins yellow or reddish brown. 13 Yucca reverchonii

 

14 (9) Mature plants caulescent, arborescent, with thick stems 0.6–2.5 m, rarely acaulescent; rosettes usually large. (15)

+ Mature plants acaulescent or occasionally caulescent with stems to 1 (rarely –2) m, sometimes indistinctly arborescent; rosettes usually small. (16)

 

15 (14) Mature plants distinctly arborescent, solitary or forming small colonies; stems 1–7 per colony, erect, 1–2.5 m. 14 Yucca elata

+ Mature plants not distinctly arborescent, forming large colonies; stems usually 7 or more per colony, often procumbent, 0.6–1.3 m. 15 Yucca utahensis

 

16 (14) Leaf blade usually soft and limp, rarely erect and rigid, 1–5 cm wide, proximal leaves often becoming reflexed; inflorescences paniculate. (17)

+ Leaf blade rigid or sometimes flexible, including proximal leaves, usually less than 2 cm wide, or if wider, then inflorescences racemose and partially held within rosettes; inflorescences racemose or paniculate. (19)

 

17 (16) Tepals 5–7 cm; inflorescences glabrous. 16 Yucca filamentosa

+ Tepals 3–5 cm; inflorescences pubescent or glabrous. (18)

 

18 (17) Inflorescences pubescent. 17 Yucca flaccida

+ Inflorescences glabrous. 25 Yucca necopina

 

19 (16) Inflorescences paniculate (and racemose distally in Y. constricta); leaf blade plano-convex or sometimes plano-keeled. (20)

+ Inflorescences primarily racemose, occasionally paniculate proximally; leaf blade concave or concavo-convex, except for those less than 0.9 cm wide, then plano-convex or plano-keeled. (22)

 

20 (19) Distance from leaf tips to proximal inflorescence branches less than twice leaf length when fully expanded; peduncle 0.5–1 m; leaf blade 0.3–0.7(–1.5) cm wide. 28 Yucca campestris

+ Distance from leaf tips to proximal inflorescence branches more than twice leaf length when fully expanded; peduncle 1–2 m; leaf blade (0.3–)0.7–2 cm wide. (21)

 

21 (20) Capsules not constricted; leaf blade mostly recurving, 1–2 cm wide. 26 Yucca tenuistyla

+ Capsules deeply constricted near middle; leaf blade mostly linear, (0.3–)0.7–1.5 cm wide. 27 Yucca constricta

 

22 (19) Peduncle (0.1–)0.3–2.5 m; inflorescences arising well beyond rosettes. (23)

+ Peduncle 0.1–0.6 m; inflorescences arising within or just beyond rosettes. (24)

 

23 (22) Leaf blade usually linear, 20–80 (–150) cm, not glaucous; inflorescences (4–)8–20 dm. 18 Yucca angustissima

+ Leaf blade spatulate-lanceolate, 15–46 cm, rather glaucous; inflorescences 4–7 dm. 21 Yucca neomexicana

 

24 (22) Capsules 3–5.5(–7) Χ 2–3 cm. (25)

+ Capsules (3–)5–7(–9) cm Χ 2–4(–5) cm. (27)

 

25 (24) Peduncle shorter than 0.2 m. 20 Yucca harrimaniae

+ Peduncle (0.1–)0.2 m or longer. (26)

 

26 (25) Style pale green or rarely white; Colorado, New Mexico, Oklahoma panhandle. 21 Yucca neomexicana

+ Style dark green; Arkansas, Kansas, Missouri, Oklahoma, Texas. 22 Yucca arkansana

 

27 (24) Leaf blade 0.7–4.3 cm wide. (28)

+ Leaf blade 0.5–2(–2.5) cm wide. (29)

 

28 (27) Style pale to bright green; leaf blade 1.8–4.3 cm wide; Arizona, Colorado, Nevada, New Mexico, Utah. 20 Yucca harrimaniae

+ Style dark green; leaf blade 0.7–2.5 cm wide; Arkansas, Kansas, Missouri, Oklahoma, Texas. 22 Yucca arkansana

 

29 (27) Style dark green. (30)

+ Style white or pale yellowish green. (31)

 

30 (29) Inflorescences 5–10 dm; leaf blade 0.8–1.2 cm wide, rigid. 24 Yucca glauca

+ Inflorescences 3–6(–8) dm; leaf blade 0.7–2(–2.5) cm wide, flexible. 22 Yucca arkansana

 

31 (29) Inflorescences 2.5–4.5(–8.5) dm; peduncle shorter than 0.2 m. 19 Yucca baileyi

+ Inflorescences (5–)7–13 dm; peduncle 0.1–0.5 m. 23 Yucca intermedia

 

Key to the Parryanae Agaves

1.         Leaves relatively short, broad, short acuminate, mostly 2–3 1/2 times longer than broad; spines 2–3 cm long; flowers relatively large, mostly 60–90 mm long................................................................................... 2

1.         Leaves relatively narrow, more acuminate, mostly 3 1/2 –6 times longer than broad; spines more variable, 2–5 cm long; flowers smaller, mostly 40–60 mm long.......................................................................... 5

2.         Rosettes globose, suckering copiously with long rhizomes, forming large, spreading clones; panicles deep, with 20–40 umbels; flowers 60–80 mm long....................................................................................... 3

2.         Rosettes not globose, more openly flat-topped, with few or no suckers; panicles rather wide and open with 10–20 large umbels; flowers 67–90 mm long..................................................................................... 7

3.         Rosettes large with many leaves; mature leaves 20–40 cm long, acuminate................................

            ................................................................................................................ Agave parryi p 538

3.         Rosettes small with few leaves; mature leaves 10–30 cm long, truncate to short acuminate........ .           

            ............................................................................................................................................. 4

4.         Leaves of mature wild plants 10–20 cm long, not mammillate, the margins straight or nearly so; inflorescence more compact with 20 or more branches..........................................................................................

            ...................................................................................................... Agave parryi var truncata

4.         Leaves of mature wild plants 20–30 cm long, conspicuously mammillate toward apex; inflorescence laxly elongate with 15–20 small, remote umbels ......................................................... Agave guadalajarana

5.         Leaves ovate lanceolate, short acuminate 20–30 cm long, with short spines 2–3 cm long; flowers with well developed tubes, ca. 1/2 as long as tepals. Central Arizona...................................................... .

            ........................................................................................................ Agave parryi var couesii

5.         Leaves lanceolate, acuminate 20–35 cm long, frequently with subulate spines 3–5 cm long; flowers with deep or shallow tubes......................................................................................................................... 6

6.         Flowers larger, mostly 55–67 mm long, with deeper tubes (10–14 mm); spring flowering..........

            ............................................................................................................... Agave neomexicana

6.         Flowers smaller, mostly 40–55 mm long, with shallow tubes (5–7 mm); fall flowering................

            .................................................................................................................... Agave gracilipes

7.         Leaves larger, 30–70 ΄ 15–25 cm, long acuminate; teeth reflexed along middle and lower leaf margins; tepals about equaling to slightly longer than tube; Big Bend Region and adjacent Mexico............................ 8

7.         Leaves smaller, 20–30 ΄ 10–12 cm, the apex abruptly acute; teeth not reflexed along margins; tepals about twice as long as tube; Sierras of southern Coahuila.................................................................................

            ................................................................................................................... Agave parrasana

8.         Leaves relatively long and narrow, 30–70 ΄ 15–25 cm, the length 2 or more times the width, ovate-acuminate to long acuminate, leaf tip acute, glaucous gray to light green, spine stouter, 3–5 (-10) cm long, flowers 68–88 mm long, tepals 18–24 mm long; Big Bend, east-central Chihuahua and northwestern Coahuila, Mexico.     

            ................................................................................................................. Agave havardiana

8.         Leaves relatively short and broad, 35–45 ΄ 20–24 cm, the length less than 2 times the width, elliptic to ovate-elliptic, leaf tip obtuse, silver-blue to grayish sky blue, spine 2 cm long; flowers 67–74 mm long, tepals 15–17 mm long, Nuevo Leσn, Mexico.................................................................................... Agave ovatifolia

 

Mountain States Wholesale Nursery  webmaster george@mswn.com January 06, 2009