GROUP H: Leaves simple, alternate, evergreen, most > 4.5 mm wide
KEY TO GENERA
1. Plant armed with thorns, sometimes quite scarce ................................................................................................... 2
2. Petiole winged, most 15-37 mm ....................................................................................................... Citrus
2. Petiole not winged, most 0-15 mm ................................................................................................................................ 3
3. Leaf blade underside with silver and russet peltate scales ................................................................ Elaeagnus
3. Leaf blade underside with no peltate scales ....................................................................................................... 4
4. Twigs terete or nearly so. Stamens 20. Fruits 5 separate nutlets adhering to inside of a fleshy cup….. Pyracantha
4. Twigs ridged, especially below petioles. Stamens 4, 5, or 10. Fruits drupes or berries ....................... 5
5. Leaf scars scarcely raised, nearly parallel with twig. Leaves distinctly one per node…………. Ximenia
5. Leaf scars raised, at ca 20-40 ° with twig. Leaves basically one per node but often with l-few from leaf axils and/or leaves closely clustered on stubby lateral twigs ............................................................................. 6
6. Wood of year 2 twigs hard to cut; outer margin of pith of year 1 twigs light-colored. Most leaves usually closely clustered on stubby lateral twigs. Stamens 10: 5 with anthers and 5 petallike. Fruits 1-seeded drupelike berries .................................................................................................................................. Sideroxylon
6. Wood of year 2 twigs easy to cut; outer margin of pith of year 1 twigs greenish. 1-few leaves from axils of main leaves. Stamens 5. Fruits few- to many-seeded berries (See GROUP A) .................. Lycium
1. Plant lacking thorns but perhaps bearing prickles or spines ............................................................................................. 7
7. Stems mostly trailing or creeping on or just below ground litter, some decumbent, others generally to 40 cm and breadth more than height ............................................................................................................... 8
8. All leaf blades entire .............................................................................................................................................. 9
9. Twigs and leaves densely and completely covered with hairs, the epidermis hidden ............. Lupinus
9. Twigs and leaves having all or some parts glabrous OR hairs present and the epidermis easily visible 10
10. Leaf blade underside with peltate glands in pits .................................................................. Morella
10. Leaf blade underside lacking such glands ................................................................................... 11
11. Leaf blade mostly 15-60 mm across ............................................................................. Epigaea
11. Leaf blade under 15 mm across ............................................................................................ 12
12. Leaf blade with well-scattered bristly hairs on underside................................................................ Gaultheria
12. Leaf blade lacking such hairs on underside .............................................................. 13
13. Leaf blade underside light-colored with a dense covering of fine white hairs ….. Andromeda
13. Leaf blade underside greenish and glabrous or with scattered fine hairs .... 14
14. Leaf blade spatulate .............................................................. Arctostaphylos
14. Leaf blade elliptic to oblong or orbicular (See GROUP A) … Leiophyllum , Vaccinium
8. Some or all leaf blades finely to coarsely crenate or serrate, sometimes minutely so and quite scattered 15
15. Largest leaf blade less than 2 X as long as wide .................................................................................... 16
16. Petiole 40-168 mm ..................................................................................................................... Shortia
16. Petiole 0.5-7 mm ............................................................................................................................... 17
17. Axillary buds at ca 80 ° with twig. Leaf blade apex acute to acuminate ................. Gaultheria
17. Axillary buds flattened against twig. Leaf blade apex obtuse to rounded ........ Gaylussacia
15. Largest leaf blade more than 2 X as long as wide .................................................................................. 18
18. Leaf blade distinctly widest toward apex ........................................................................ Chimaphila
18. Leaf blade mostly widest near middle or toward base .................................................................. 19
19. Leaf blade mostly distinctly widest toward base.......................................................................................... Chimaphila
19. Leaf blade mostly widest at or near middle .......................................................................... 20
20. Petioles all or most over 2 mm. Fruits capsules ................................................... Pieris
20. Petioles commonly 1.5-2 mm. Fruits berries .................................................. Vaccinium
7. Stems erect, spreading, or decumbent but most not trailing or creeping ............................................................... 21
21. Pith of year 2 twigs chambered, sometimes mostly continuous, or space mostly hollow ........................... 22
22. Twig and both leaf blade surfaces quite densely and conspicuously hairy, hiding epidermis........ Lupinus
22. Twig and leaf blades glabrous or not densely hairy .............................................................................. 23
23. Leaf blade entire or some with 1-3 teeth on each edge, epidermis visible ................................. 24
24. Leaf blade to l0 mm across .................................................................................................. Iva
24. Leaf blade mostly 25-60 mm across ....................................................................... Symplocos
23. Leaf blade toothed, teeth many more than 3 on each edge ......................................................... 25
25. Axillary buds prominently flattened. Stipules dark, linear, borne on basal edges of petiole ….. Stillingia
25. Axillary buds conical. Stipules absent ........................................................................ Agarista
21. Pith of year 2 twigs continuous, not chambered .............................................................................................. 26
26. Leaf blade crenate, serrate, toothed, or spiny, these sometimes few, very small, and confined to a few scattered leaves............................. 27
27. Leaf blade with hard spiny teeth on margin, rarely with only one spine, it on the apex ........ Ilex
27. Leaf blade lacking spines ............................................................................................................... 28
28. Leaf blade underside with small brownish peltate scales, without glandular hairs …… Chamaedaphne
28. Leaf blade underside lacking brownish peltate scales; glabrous, hairy, glandular ......... 29
29. Leaf blade underside densely hairy. hairs fine and rusty, rare escape of southern areas….. Eriobotrya
29. Leaf blade underside glabrous or, if hairy, not densely so and rusty ..................... 30
30. Plant under 40 cm. Leaf blade margin partly to entirely minutely and shallowly crenate……… Licania
30. Plant well over 40 cm. Leaf blade margin partly to entirely crenate, serrate, or toothed………31
31. Leaf blade margin partly or all crenate or serrate, some teeth below middle ……..32
32. Leaf blade leathery, upperside glossy; margin with wide crenations, these crimped downward and swollen at sinuses, making the margin thus corrugated to touch. Rare escape of southern areas ........................................................ Ardisia
32. Leaf blade leathery or not, glossy or not, margin lacking above characteristics…. 33
33. Vigorous year 1 twigs mostly over 3 mm across ................. 34
34. Leaf blade with small blunt teeth .................................................. Gordonia
34. Leaf blade sharply serrate ................................... Photinia
33. Vigorous year 1 twigs mostly under 3 mm across .............. 35
35. Leaf blade margin cut into sharp straight uneven-sized teeth, base of blade cuneate to acute (See GROUP K) ....................... Spiraea
35. Leaf blade with even-sized crenations or serrations or nearly so, base of blade broadly acute to obtuse ............................................... 36
36. End bud a terminal one ..................................... Ilex
36. End bud an axillary one ......................................... 37
37. Basal portion of some petioles terete, others partly so.......................................... Leucothoe
37. Basal portion of all petioles only partly terete …….38
38. Axillary buds at ca 40-80 ° with twig ….. Vaccinium
38. Axillary buds flattened and appressed against twig or divergent to 35 ° ................................ 39
39. Leaf blade midvein faintly or barely reaching blade apex, the tip not swollen................................ Stillingia
39. Leaf blade midvein reaching apex, pro-truding, the tip promi-nently swollen (See GROUP K) ….. Lyonia
31. Leaf blade margin mostly entire below middle; above the middle crenate, serrate, or coarsely toothed ........................... 40
40. Larger leaf blades coarsely few-toothed or with few pointed lobes 41
41. Leaf blade thick, fleshy, and juicy when crushed ............... 42
42. Leaf blade (14)20-53 X 10-23 mm; stipules light amber to maroon, to 0.7 X 0.3 mm ...................................................................... Maytenus
42. Leaf blade (30)40-80(102) X 20-50 mm; stipules absent …….. Scaevola
41. Leaf blade lacking one to all of the above characters ........ 43
43. End bud a terminal one ...................................... Quercus
43. End bud axillary ................................................ Baccharis
40. Larger leaf blades all or some crenate or serrate .......................... 44
44. Twigs with long sharp appressed hairs................................................................... Pieris
44. Twigs with other types of hair or glabrous............................................................ 45
45. End bud a terminal one ................................................ 46
46. Stipules absent ............................................. Morella
46. Stipules present ................................................... Ilex
45. End bud an axillary one ............................................... 47
47. Stipules absent ............................................. Morella
47. Stipules present on young twigs…………………. 48
48. Petiole basal portion terete when well separated from axillary bud………….. Leucothoe
48. Petiole basal portion flattened or grooved on upperside when separated from axillary bud…………. 49
49. Leaf blade surfaces bearing only erect black-headed hairs, scanty on upperside, scattered on underside…….. Pieris
49. Leaf blade surfaces glabrous or bearing other types of hairs…………… Vaccinium
26. Leaf blade margin entire, some times undulate or shallowly lobed but lobes with margin entire ...... 51
50. Twigs and both leaf blade surfaces quite densely and conspicuously long-hairy, hiding epidermis…….. Lupinus
50. Twigs and leaf blade surfaces glabrous, or hairy but not densely long hairy on all three of the above surfaces, epidermis evident…..51
51. Leaf blade underside with tiny silvery to rusty peltate scales (use l0 X lens), persistent scales often widely spaced with age………..52
52. Scales silvery, overlapping ................................................................................. Croton
52. Scales tan to rusty, not overlapping or only rarely so ............................................. 53
53. Leaf blade base obtuse to rounded and abruptly short-tapered onto petiole. Flowers in terminal clusters..................................................................... Rhododendron
53. Leaf blade base acute and long-tapered onto petiole Flowers in axillary clusters…….. Lyonia
51. Leaf blade underside lacking scales, glabrous or variously hairy........................................................................... 54
54. Leaf blade underside densely hairy ............................................................................ 55
55. Petiole mostly over 7 mm ............................................................................. Croton
55. Petiole 1-5 mm ..................................................................................................... 56
56. Leaf blade mostly 8-30 mm across. Fruits acorns 9-20 mm ......... Quercus
56. Leaf blade mostly 4-10 mm across. Fruits capsules 5-7 mm ………. Helianthemum
54. Leaf blade underside glabrous or not densely hairy ................................................ 57
57. Leaf blade surfaces with minute resin-bearing glands…………58
58. Leaf blade under 4 X as long as wide……………….. Dodonaea
58. Leaf blade over 4 X as long as wide (See GROUP A) ............... Chrysoma
57. Leaf blade surfaces lacking minute resin-bearing glands .............................. 59
59. Foliage and/or twigs distinctly aromatic when crushed or bruised ..... 60
60. Leaf blade mostly 15-35 mm .................................................. Garberia
60. Leaf blade mostly over 45 mm ......................................................... 61
61. Leaf blade midrib visible but lateral veins indistinct or not evident; underside bearing minute pale glandular dots….. Illicium
61. Leaf blade midrib and major lateral veins prominent; underside lacking glandular dots…….. Persea
59. Foliage and twigs not distinctly aromatic when crushed or bruised, possibly with another strong odor……….62
62. Two conspicuous glands (opposite each other or not) on petiole and/or basal edges of leaf blade….. Conocarpus
62. No such glands present .................................................................. 63
63. Twigs with hairs ca 1 mm or more ........................................ 64
64. Leaf blade 5-15 mm ................................................ Kalmia
64. Leaf blade 20-80 mm ..................................................... 65
65. Leaf blade surfaces with tiny short-stalked glands……… Pieris
65. Leaf blade without stalked glands………………… 66
66. Twigs with some hairs over 2 mm 25…………… Bejaria
66. Twigs with hairs to 1.5 mm (see GROUP J)……….. Gaylussacia
63. Twigs glabrous or with all hairs under 0.9 mm .................... 67
67. Plant under 40 cm. Leaf blade oblanceolate, 10-35 mm across, upper surface glabrous, shiny, and with netvein system prominently raised…….. Licania
67. Plant usually over 40 cm. Leaf blade lacking above combination of characters………68
68. Leaf blades mostly under 12 mm across ..................................................... 69
69. Year 1 twigs strongly multi-ribbed. Leaf blade somewhat fleshy, with 3 long veins clearly evident (the midvein and 2 smaller lateral ones)…….. Iva
69. Year 1 twigs smoothly terete or weakly ribbed. Leaf blade firm to soft leathery but not fleshy, only one long vein evident, the midvein………70
70. Leaf scars at 90 ° or nearly so. Lower portion of petiole essentially parallel with twig (See GROUP A) ………… Leiophyllum
70. Leaf scars at ca 10-45 ° or indistinct. Lower portion of petiole at an angle with twig .................................... 71
71. Buds densely hairy, scales absent………………………………… Helianthemum
71. Buds glabrous or slightly hairy, scales present……………………..72
72. Vigorous twigs with 1 leaf at tip .................................................................................................... Ilex
72. Vigorous twigs with 2-4 leaves at tip .............................................................................................. 73
73. Petiole 1-3 mm. Fruits acorns 9-20 mm ............................................................ Quercus
73. Petiole essentially absent, winged to base. Fruits achenes 1-15 mm ....... .. Baccharis
68. Leaf blades mostly over 12 mm across................................................................................................ 74
74. Leaf blade thick, fleshy, and juicy when crushed ............................................................. 75
75. Leaf blade (14)20-53 X (14)10-23 mm ......................................................... Maytenus
75. Leaf blade (30)40-80(102 X 20-50 mm ............................................... Scaevola
74. Leaf blade not thick, fleshy, and juicy when crushed ............................................................................ 76
76. Vigorous twigs with l leaf at end, although leaves often clustered at tip of stubby twigs, especially on lateral ones…..77
77. Buds superposed at some nodes. Leaf blade underside much whitened, apex rounded .. .. Maytenus
77. Buds not superposed. Leaf blade underside not whitened, sometimes pale-green, apex acute or acuminate to rounded or sometimes slightly mucronate…………..78
78. Leaf blades mostly less than 2.2 X as long as wide, major lateral veins on upperside prominent and raised. Ovary inferior……………. Vaccinium
78. Leaf blades mostly more than 2.2 X as long as wide, major lateral veins on upperside not prominent, little raised, if any. Ovary superior or inferior……..79
79. End bud terminal ................................................... 80
80. Stipules present and persistent (minute, dark, or dark-tipped, triangular and sharp-pointed, most likely seen at juncture of current and previous year stems, both terminal and lateral) .......... Ilex
80. Stipules absent ................................................... Ardisia
79. End bud axillary .................................................................... 81
81. Leaf blade 10-105 mm; upperside glabrous………………………………… Lyonia
81. Leaf blade 12-48 mm; upperside with curled hairs ca 0.25 mm (See GROUP J)………. Gaylussacia
76. Vigorous twigs with 2 or more leaves clustered at tip .......................................................... 82
82. Petioles mostly 8-40 mm ............................................................... 83
83. Largest year 1 twigs 3 mm or more across. Fruits columnar………….. Rhododendron
83. Largest year 1 twigs under 3 mm across. Fruits depressed-globose…………….. Kalmia
82. Petioles mostly 0-8 mm measured to base of the sometimes much-tapered blade ............................. 84
84. Leaf blade surfaces with minute dots or glands ............................................................................ 85
85. Twigs prominently ridged; leaf scars indistinct ..................................................... Baccharis
85. Twigs terete or somewhat undulating; leaf scars evident .................................................. 86
86. Leaf scars with 3 bundle scars. Leaf margin thickened and downcurved; petiole 0-3 mm…….. Morella
86. Leaf scars with 1 bundle scar. Leaf blade margin thin, sometimes slightly downcurved; petiole mostly 3-6 mm……. Myrsine
84. Leaf blade surfaces without minute glands or dots ...................................................................... 87
87. Leaves (1)2 at end of leading twigs, apical internode commonly ca 1 mm across ……. Solanum
87. Leaves (2)3 or more at tip of leading twigs, apical internode commonly 2 mm or more across…… Quercus