1	"Stipules knob-like, corky, thick, bases persistent; leaves generally opposite (generally alternate in <i>Ceanothus megacarpus</i> var. <i>megacarpus</i>, <i>Ceanothus verrucosus</i>), clustered or not; inflorescence generally umbel-like (subg. <i>Cerastes</i>)"	2
1	"Stipules scale-like, thin, deciduous; leaves alternate; inflorescence generally raceme- to panicle-, occasionally +- umbel-like (subg. <i>Ceanothus</i>)"	36
2	"Leaves generally alternate"	3
2	"Leaves generally opposite, occasionally clustered"	4
3	"Leaf blade 10--25 mm, 5--12 mm wide, length generally > 2 &times; width, elliptic to widely oblanceolate, margin entire; fruit 7--12 mm wide"	"Ceanothus megacarpus var. megacarpus"
3	"Leaf blade 5--14 mm, 3--10 mm wide, length generally < 2 &times; width, widely obovate to round, margin entire or teeth +- sharp; fruit 4--6 mm wide"	"Ceanothus verrucosus"
4	"Plant mat- to mound-like, generally < 1 m; stems spreading, +- ascending, occasionally arched, rooting at nodes or not"	5
4	"Plant generally erect, 1--4+ m; stems ascending to erect, occasionally intricately branched, not rooting at nodes"	18
5	"Leaf margin generally entire, occasionally +- 3--5-toothed distally"	6
5	"Leaf blade margin 2--35-toothed"	9
6	"Leaf blade 8--20 mm, gray-tomentose abaxially, margin thick or +- rolled under; CCo (nw San Luis Obispo Co.), < 60 m"	"Ceanothus maritimus"
6	"Leaf blade generally 4--12 mm, +- glabrous to strigose abaxially, margin not thick, +- not rolled under; KR, n NCoR, n&c SN, > 260 m"	7
7	"Leaves generally clustered, generally erect"	"Ceanothus roderickii"
7	"Leaves +- evenly spaced, generally not clustered, spreading to ascending"	8
8	"Plant generally mound-like, generally 0.3--1 m, stems not rooting at nodes; twigs brown to gray-brown"	"Ceanothus arcuatus"
8	"Plant mat-like, < 0.3 m, stems rooting at nodes; twigs generally red-brown"	"Ceanothus fresnensis"
9	"Leaf blade generally wide-elliptic or -obovate or round, length generally < 2 &times; width;, margin 5--35-toothed"	10
9	"Leaf blade generally elliptic to obovate or oblanceolate, length generally > 2 &times; width; margin 2--11-toothed"	13
10	"Twigs generally not angled; flowers white to pale blue or blue-lavender"	11
10	"Twigs generally angled distally; flowers blue to blue-purple"	12
11	"Leaf blade 10--20 mm; fruit 6--9 mm wide; horns 1--2 mm, wrinkled; KR (Trinity Mtns), s SNH (Kern Plateau), 1050--2750 m"	"Ceanothus pinetorum"
11	"Leaf blade 4--10 mm; fruit 4--6 mm wide; horns < 1 mm, smooth; CCo, < 400 m"	"Ceanothus rigidus"
12	"Plant < 0.3 m; stems generally spreading; leaf blade 23--31 mm, margin 13--35-toothed"	"Ceanothus gloriosus var. gloriosus"
12	"Plant < 0.5 m; stems spreading to +- ascending; leaf blade 10--21 mm, margin 9--19-toothed"	"Ceanothus gloriosus var. porrectus"
13	"Leaf blade 2--6 mm wide, margin 0--5-toothed distally"	14
13	"Leaf blade 4--16 mm wide, margin generally 2--11-toothed distally"	15
14	"Leaves not clustered, spreading, tips generally truncate, margin generally 2--3-toothed; KR, NCoR"	"Ceanothus pumilus"
14	"Leaves generally clustered, generally erect, tips obtuse to +- notched, margin 0--5-toothed; n SNF (w El Dorado Co.)"	"Ceanothus roderickii"
15	"Leaf blade generally not +- wavy, generally not +- folded lengthwise; fruit 6--9 mm wide, horns 1--2 mm, thick, wrinkled (slender in <i>Ceanothus prostratus</i> var. <i>occidentalis</i>)"	16
15	"Leaf blade generally +- wavy or +- folded; fruit 4--6 mm wide, horns 1.5--2.5 mm, +- slender, smooth"	17
16	"Plant mound-like; leaf blade +- folded lengthwise, concave adaxially, teeth 5--9, in distal 1/2; fruit horns spreading"	"Ceanothus prostratus var. occidentalis"
16	"Plant generally mat-like; leaf blade +- not folded lengthwise, not concave adaxially, teeth 3--5(7), in distal 2/3; fruit horns erect"	"Ceanothus prostratus var. prostratus"
17	"Plant mound-like, 0.2--0.5 m, stems spreading to +- ascending, occasionally rooting at nodes"	"Ceanothus confusus"
17	"Plant erect to mound-like, 0.5--1.5 m, stems ascending to +- erect, generally not rooting at nodes"	"Ceanothus divergens"
18	"Leaf blade +- wavy to +- folded lengthwise, margin teeth spine-like"	19
18	"Leaf blade generally flat or convex to concave adaxially, margin entire or teeth +- sharp, not spine-like"	22
19	"Leaf blade elliptic to narrowly obovate"	"Ceanothus divergens"
19	"Leaf blade widely elliptic to +- round"	20
20	"Leaves +- spreading, margin 3--5-toothed"	"Ceanothus sonomensis"
20	"Leaves generally reflexed, margin 7--15-toothed"	21
21	"Sepals, petals 6--8; fruit 5--7 mm, wrinkled, horns thick; flowers white to blue; generally serpentine"	"Ceanothus jepsonii"
21	"Sepals, petals 5; fruit 4--5 mm, smooth, horns slender; flowers dark blue to purple; volcanic substrates"	"Ceanothus purpureus"
22	"Leaf blade densely tomentose abaxially, veins obscure, margin generally rolled under"	"Ceanothus crassifolius var. crassifolius"
22	"Leaf blade generally glabrous to strigose or puberulent abaxially (sparsely tomentose in <i>Ceanothus crassifolius</i> var. <i>planus</i>, +- tomentose in <i>Ceanothus otayensis</i>), veins generally evident, margin not rolled under (except <i>Ceanothus otayensis</i>)"	23
23	"Leaf margin generally entire, or teeth < 5, unevenly distributed"	24
23	"Leaf margin generally dentate to +- serrate, teeth generally 5--35 (occasionally < 5 in <i>Ceanothus vestitus</i>), +- evenly distributed, or in distal 1/2, occasionally minute"	30
24	"Leaf blade 3--7 mm, 1--3 mm wide, narrow-oblanceolate to -obovate; inflorescence generally < 1 cm; flowers generally pale blue, occasionally +- pink"	"Ceanothus ophiochilus"
24	"Leaf blade 5--30 mm, 3--19 mm wide, elliptic, oblanceolate, obovate, or +- round; inflorescence generally 1--2 cm; flowers generally white (pale blue to lavender in some <i>Ceanothus cuneatus</i>)"	25
25	"Flower disk dark; fruit 5--12 mm wide"	26
25	"Flower disk generally not dark, white to pale blue or lavender; fruit 3--6 mm wide"	27
26	"Leaf tip obtuse to rounded; fruit 5--9 mm wide; s SCoRO, WTR (Santa Barbara, Ventura cos.)"	"Ceanothus crassifolius var. planus"
26	"Leaf tip truncate to +- notched; fruit 7--12 mm wide; ChI"	"Ceanothus megacarpus var. insularis"
27	"Twigs generally dense-puberulent to short-tomentose, pale gray to +- white; leaf blade short-curly-puberulent abaxially"	"Ceanothus vestitus"
27	"Twigs generally glabrous to +- puberulent, generally brown to gray-brown, leaf blade glabrous to +- strigose abaxially"	28
28	"Flower generally white; twigs generally gray-brown; leaf blade tip acute to +- rounded"	"Ceanothus cuneatus var. cuneatus"
28	"Flower generally blue to lavender; twigs generally brown; leaf blade tip truncate to notched"	29
29	"Leaves at nodes and in axillary clusters, node leaves widely obovate, clustered leaves oblanceolate to narrowly obovate"	"Ceanothus cuneatus var. fascicularis"
29	"Leaves at nodes, blades widely obovate to +- round"	"Ceanothus cuneatus var. ramulosus"
30	"Twigs generally angled, especially distally"	31
30	"Twigs generally not angled"	32
31	"Leaf blade 13--45 mm, widely obovate to +- round, margin 13--35-toothed"	"Ceanothus gloriosus var. exaltatus"
31	"Leaf blade 7--21 mm, obovate to narrowly obovate, margin 9--17-toothed"	"Ceanothus masonii"
32	"Leaf blade generally 10--25+ mm"	33
32	"Leaf blade generally <= 12 mm (except some <i>Ceanothus vestitus</i> 5--20 mm)"	34
33	"Leaf blade dark green, obovate to widely elliptic; fruit 6--9 mm wide, +- wrinkled, horns 1--2 mm; se SnFrB (Santa Clara Co.)"	"Ceanothus ferrisiae"
33	"Leaf blade green to yellow-green, widely elliptic to +- round; fruit 3--5 mm wide, generally smooth or +- 3-bulged distally, horns < 1 mm or 0; e TR, PR"	"Ceanothus perplexans"
34	"Leaf blade +- tomentose abaxially, glabrous in age, veins obscure, margin thick or rolled under --- s PR (Otay, San Miguel mtns)"	"Ceanothus otayensis"
34	"Leaf blade glabrous to short-strigose or short-curly-puberulent abaxially, occasionally glabrous in age, veins evident, margin generally not rolled under, occasionally thick"	35
35	"Flowers generally blue to lavender (white), leaf tip rounded to truncate, margin entire or 5--9-toothed"	"Ceanothus rigidus"
35	"Flowers generally white; leaf tip generally acute to obtuse, margin entire or 3--5-toothed"	"Ceanothus vestitus"
36	"Twigs rigid, generally thorn-like"	37
36	"Twigs flexible, not thorn-like"	40
37	"Leaf blade 1-ribbed from base, shiny green adaxially; twigs green"	"Ceanothus spinosus"
37	"Leaf blade 3-ribbed from base, dull green adaxially; twigs pale gray to gray-green"	38
38	"Plant generally < 1.5 m; stems generally spreading; inflorescence 1--4 cm, generally sessile"	"Ceanothus cordulatus"
38	"Plant generally 1.5--4 m; stems ascending to erect; inflorescence 3--15 cm, generally stalked"	39
39	"Leaf blade wide-elliptic to -ovate, 20--50+ mm, 10--45 mm wide; fruit coarse-wrinkled when dry"	"Ceanothus incanus"
39	"Leaf blade elliptic to ovate, 12--30 mm, 3--15 mm wide; fruit smooth to +- wrinkled when dry"	"Ceanothus leucodermis"
40	"Leaf blade generally 1-ribbed from base"	41
40	"Leaf blade generally 3-ribbed from base"	56
41	"Plant mat- to mound-like, generally < 0.5 m; stem spreading to ascending"	42
41	"Plant generally erect, occasionally tree-like, > 0.5 m (occasionally mound-like in <i>Ceanothus papillosus</i>); stem ascending to erect"	45
42	"Leaf margin rolled under; blade tomentose abaxially, tip truncate to notched"	"Ceanothus hearstiorum"
42	"Leaf margin not rolled under; blade glabrous, puberulent, or short-wavy-hairy abaxially, tip acute to +- rounded"	43
43	"Petiole 1--3 mm; leaf blade +- wavy, +- folded lengthwise, glabrous abaxially except veins; margin entire to few-toothed distally"	"Ceanothus foliosus var. vineatus"
43	"Petiole 3--11 mm; leaf blade generally not +- wavy, not +- folded lengthwise, puberulent to tomentose abaxially; margin 27--45-toothed"	44
44	"Plant generally mat-like, generally < 0.3 m, rooting at nodes; inflorescences on short, erect twigs; twigs green, occasionally tinged red"	"Ceanothus diversifolius"
44	"Plant erect to mound-like, 0.5--1 m, not rooting at nodes; inflorescences not on short, erect twigs; twigs pale green to gray-green"	"Ceanothus lemmonii"
45	"Leaf blade margin thick or rolled under"	46
45	"Leaf blade margin generally not thick, generally not rolled under (partly rolled under in <i>Ceanothus parryi</i>)"	49
46	"Leaf blade widely ovate to +- round, furrowed along veins adaxially, tip acute to obtuse"	47
46	"Leaf blade +- oblong or narrowly elliptic, not furrowed adaxially, tip truncate to notched"	48
47	"Leaf blade 5--14 mm; plant 0.5--1.5 m, generally dense"	"Ceanothus impressus var. impressus"
47	"Leaf blade 11--25 mm; plant 1--3 m, generally open"	"Ceanothus impressus var. nipomensis"
48	"Plant generally 0.5--1.5 m; leaf blade 4--16 mm, 2--8 mm wide, not glandular-papillate adaxially, glandular-papillate near margin"	"Ceanothus dentatus"
48	"Plant 1--3.5 m; leaf blade 11--50 mm, 6--15 mm wide, glandular-papillate adaxially and on margin"	"Ceanothus papillosus"
49	"Leaf margin generally gland-toothed, glands generally dark, +- persistent"	50
49	"Leaf margin generally entire (or minutely gland-toothed, glands not dark, not persistent)"	53
50	"Leaf margin +- rolled under, especially below middle, occasionally minutely glandular; blade cobwebby to loose-tomentose abaxially"	"Ceanothus parryi"
50	"Leaf margin entire or minutely gland-toothed; blade glabrous to puberulent abaxially"	51
51	"Twigs pale green to gray-green; petiole 3--6 mm; leaf blade flat"	"Ceanothus lemmonii"
51	"Twigs green to red-green; petiole 1--3 mm; leaf blade generally wavy, +- folded lengthwise"	52
52	"Leaf blade +- glabrous to sparsely puberulent abaxially; plants +- open"	"Ceanothus foliosus var. foliosus"
52	"Leaf blade densely short-wavy-hairy abaxially; plants +- dense"	"Ceanothus foliosus var. medius"
53	"Plant generally < 1.5 m, stems +- spreading to generally ascending; leaf blade tip obtuse; inflorescence 4--9 cm, raceme- to panicle-like; SNH"	"Ceanothus parvifolius"
53	"Plant generally 1--6 m, occasionally tree-like, stems ascending to erect; leaf blade tip acute to obtuse; inflorescence 4--21 cm, generally panicle-like; not SNH"	54
54	"Flowers blue to pale blue; leaf blade generally dark shiny green adaxially --- s SCoRO, WTR, PR"	"Ceanothus spinosus"
54	"Flowers white; leaf blade generally dull to light green adaxially, occasionally shiny"	55
55	"Leaf blade elliptic to +- oblong, thin; fruit 4--6.5 mm wide; sw SnFrB (Santa Cruz Mtns)"	"Ceanothus integerrimus var. integerrimus"
55	"Leaf blade elliptic to oblong-ovate, +- thick; fruit 6--9 mm wide; n&c SNF, s SCoR, TR, PR"	"Ceanothus palmeri"
56	"Leaf margin entire (minutely toothed)"	57
56	"Leaf margin minutely toothed or serrate, teeth generally gland-tipped"	59
57	"Main stem generally ascending to +- spreading; leaf blade 3--12 mm wide, shiny green adaxially"	"Ceanothus parvifolius"
57	"Main stem ascending to erect; leaf blade 10--45 mm wide, dull green adaxially"	58
58	"Twigs rigid, pale gray to gray-green; leaf blade abaxially gray-green, strigose; fruit wrinkled"	"Ceanothus incanus"
58	"Twigs flexible, generally green; leaf blade abaxially pale green, glabrous to sparsely short-hairy, especially veins; fruit smooth to bulged or +- 3-ridged distally"	"Ceanothus integerrimus var. macrothyrsus"
59	"Leaf blade generally tomentose abaxially, veins +- obscured by hairs"	60
59	"Leaf blade +- glabrous to puberulent or short-wavy-hairy abaxially, veins not obscured by hairs"	61
60	"Leaf blade 25--80 mm, thick, leathery; petiole 10--25 mm; ChI"	"Ceanothus arboreus"
60	"Leaf blade 10--25 mm, generally thin, not leathery; petiole 1--3 mm; mainland"	"Ceanothus tomentosus"
61	"Leaf blade generally 25--80 mm, 13--60 mm wide, generally widely elliptic to ovate"	62
61	"Leaf blade generally 5--45 mm, 3--25 mm wide, elliptic, oblong-elliptic, oblanceolate (ovate)"	64
62	"Flowers generally blue; fruit 5--8 mm wide, black; ChI"	"Ceanothus arboreus"
62	"Flowers white; fruit 3--4.5 mm wide, brown; mainland"	63
63	"Leaf deciduous, not aromatic; blade thin, not leathery, not sticky adaxially"	"Ceanothus sanguineus"
63	"Leaf evergreen, aromatic; blade leathery, +- sticky adaxially"	"Ceanothus velutinus"
64	"Plant mat- to mound-like, generally < 1 m; stems +- ascending to spreading"	65
64	"Plant not mat- to mound-like, generally 1--4 m; stems ascending to erect"	68
65	"Twigs angled distally; leaf blade abaxial veins +- raised"	66
65	"Twigs not angled distally; leaf blade abaxial veins +- not raised"	67
66	"Twigs +- puberulent; leaf blade ovate to widely elliptic, margin rolled under"	"Ceanothus thyrsiflorus var. griseus"
66	"Twigs +- glabrous; leaf blade oblong-ovate to elliptic, margin not to partly rolled under"	"Ceanothus thyrsiflorus var. thyrsiflorus"
67	"Plant generally mat-like, generally < 0.3 m; stem rooting at nodes; twigs green, occasionally tinged red; fruit 4--5 mm wide"	"Ceanothus diversifolius"
67	"Plant +- mound-like, generally > 0.5 m, stem not rooting at nodes; twigs pale green to gray-green; fruit 3--4 mm wide"	"Ceanothus lemmonii"
68	"Twigs generally angled distally, internodes ridged"	69
68	"Twigs not angled distally, internodes not ridged"	72
69	"Leaf blade +- oblong to narrowly elliptic, length generally > 2 &times; width, cobwebby to loose-tomentose abaxially, glabrous in age"	"Ceanothus parryi"
69	"Leaf blade generally ovate to elliptic, length generally < 2 &times; width, glabrous to +- puberulent abaxially, especially on veins"	70
70	"Inflorescence 5--30 cm; twigs papillate; leaf blade abaxial veins +- not raised"	"Ceanothus cyaneus"
70	"Inflorescence 1.5--7 cm; twigs not papillate; leaf blade abaxial veins +- raised"	71
71	"Twigs +- puberulent; leaf blade ovate to widely elliptic, margin rolled under"	"Ceanothus thyrsiflorus var. griseus"
71	"Twigs +- glabrous; leaf blade oblong-ovate to elliptic, margin not to partly rolled under"	"Ceanothus thyrsiflorus var. thyrsiflorus"
72	"Leaf blade flat or generally wavy, +- folded lengthwise; petiole 1--3 mm; fruit 3--4 mm wide"	73
72	"Leaf blade generally flat; petiole 3--7 mm; fruit 4--7 mm wide"	74
73	"Leaf blade glabrous to sparsely puberulent abaxially; plant +- open"	"Ceanothus foliosus var. foliosus"
73	"Leaf blade densely short-wavy-hairy abaxially; plant +- dense"	"Ceanothus foliosus var. medius"
74	"Flower disk, ovary short-hairy; fruit prominently wrinkled"	"Ceanothus oliganthus var. orcuttii"
74	"Flower disk, ovary glabrous; fruit generally smooth or +- ridged to bulged near top"	75
75	"Twigs puberulent; leaf blade short-hairy adaxially"	"Ceanothus oliganthus var. oliganthus"
75	"Twigs +- glabrous; leaf blade glabrous to sparsely short-hairy adaxially"	"Ceanothus oliganthus var. sorediatus"