1	"Acorn cup scales thin, not tubercled, shell hairy to woolly inside, at least at tip; bark dark gray or gray-brown to black"	2
1	"Acorn cup scales generally thick, generally tubercled to +- not, shell glabrous to woolly inside; bark light gray to +- white"	10
2	"Leaf moderately to deeply lobed, lobes 1--4-toothed, teeth generally bristle-tipped; plant deciduous"	"Quercus kelloggii"
2	"Leaf entire to toothed, teeth abruptly pointed to spine-tipped, not bristle-tipped; plant evergreen"	3
3	"Leaf generally adaxially convex, margin rolled under or not, obscuring marginal teeth, blade generally widely elliptic to round; fruit mature in year 1"	4
3	"Leaf adaxially +- flat, margin not rolled under, blade generally lanceolate to oblong; fruit mature in years 1--2"	5
4	"Leaf abaxially glabrous to sparsely hairy except vein axils hair-tufted"	"Quercus agrifolia var. agrifolia"
4	"Leaf abaxially densely tomentose"	"Quercus agrifolia var. oxyadenia"
5	"Leaf abaxially +- yellow or +- white woolly; fruit mature in year 1"	"Quercus ilex"
5	"Leaf abaxially glabrous; fruit mature in year 2"	6
6	"Leaf 2--5 cm, abaxially generally +- shiny, yellow-green; nut distally acute to +- obtuse"	7
6	"Leaf 3--9(14) cm, abaxially generally +- dull; nut distally obtuse to +- rounded"	8
7	"Shrub 2--4(6) m"	"Quercus wislizeni var. frutescens"
7	"Tree generally 10--22 m"	"Quercus wislizeni var. wislizeni"
8	"Tree < 17 m --- s NCo, NCoRI, CW (except SCoRI), WTR"	"Quercus parvula var. shrevei"
8	"Shrub 1--6 m"	9
9	"Leaf margin generally entire; SCoRO (Santa Barbara Co.), n ChI (Santa Cruz Island), e WTR"	"Quercus parvula var. parvula"
9	"Leaf margin long-tapered dentate; SnFrB (Mount Tamalpais)"	"Quercus parvula var. tamalpaisensis"
10	"Acorn nut shell +- woolly inside; fruit mature in year 2; plants evergreen"	11
10	"Acorn nut shell glabrous inside; fruit mature in year 1; plants evergreen or not"	15
11	"Leaf generally 3--8 cm; acorn cup > 1.5 cm wide; generally tree, > 7 m"	12
11	"Leaf generally 1--3.5 cm; acorn cup < 1.5 cm wide (if > 1.5 cm wide, leaves <= 3 cm); generally shrub, < 7 m"	13
12	"Leaf adaxially with lateral veins +- not impressed, abaxially golden-puberulent, glabrous in age"	"Quercus chrysolepis"
12	"Leaf adaxially with lateral veins impressed, abaxially densely tomentose, sparsely tomentose in age --- ChI"	"Quercus tomentella"
13	"Twigs rigid; leaf margin wavy, strongly spine-toothed; blade elliptic to round-ovate; plants 2--6 m, erect"	"Quercus palmeri"
13	"Twigs flexible; leaf margin entire to irregularly serrate, teeth mucronate or spine-tipped; blade oblong or lanceolate to ovate; plants to 5 m, prostrate to erect"	14
14	"Leaf margin entire or with few irregular spine-tipped teeth; dry chaparral, 100--1800 m, sw PR"	"Quercus cedrosensis"
14	"Leaf margin entire to mucro-toothed; montane conifer zone, 900--2800 m, KR, NCoRH, NCoRI, CaRH, SNH, MP"	"Quercus vacciniifolia"
15	"Leaf lobed  (+- entire, wavy, or +- lobed in <i>Quercus douglasii</i>), margins generally without spines; plants deciduous"	16
15	"Leaf generally entire to toothed, not lobed, teeth with spines or not; plants generally evergreen"	23
16	"Leaf abaxially glabrous (in youth sometimes sparsely hairy), base strongly cordate, often revolute; fr on axillary peduncle (25-)35--65(-100) mm"	"Quercus robur"
16	"Leaf abaxially fine-hairy, puberulent, fine-tomentose, short-hairy, or densely appressed-stellate-hairy, base wedge-shaped, rounded-gradually tapered, or truncate (subcordate); fr subsessile or rarely on axillary peduncle to 10(-20) mm"	17
17	"Leaf shallowly lobed (sinuses generally < 1/2 distance lobe tip to midrib), adaxially generally dull, green to blue-green"	18
17	"Leaf moderately to deeply lobed (sinuses generally > 1/2 distance lobe tip to midrib), adaxially +- shiny, dark green"	20
18	"Leaf adaxially green; acorn cup scales tubercled; ChI"	"Quercus X macdonaldii"
18	"Leaf adaxially blue- or gray-green; acorn cup scales +- tubercled; mainland"	19
19	"Shrub, tree < 3 m, evergreen to deciduous; leaves 1.5--5 cm, generally irregularly coarsely toothed, adaxially blue- or gray-green"	"Quercus X alvordiana"
19	"Tree, deciduous; leaves 3--6(8) cm, +- entire, wavy, or +- lobed, adaxially blue-green"	"Quercus douglasii"
20	"Tree; acorn cup 10--30 mm deep, all scales tubercled; nut 30--50 mm, generally long-conic, distally acute to +- obtuse"	"Quercus lobata"
20	"Shrub to tree; acorn cup 4--9 mm deep, proximal scales +- tubercled, distal +- not; nut 20--30 mm, ovoid to +- spheric, distally rounded"	21
21	"Tree 8--20 m, generally with 1 trunk; terminal buds 5--12 mm, fusiform, hairs dense, +- yellow or +- white"	"Quercus garryana var. garryana"
21	"Shrub to small tree 0.3--5 m, generally with > 1 trunk; terminal buds 2--5 mm, hairs sparse, brown or +- red"	22
22	"Rays of stellate hairs on leaf abaxially generally 4--6, 0.25--0.5 mm; KR, NCoRH, CCo"	"Quercus garryana var. breweri"
22	"Rays of stellate hairs on leaf abaxially generally 6--8, < 0.3 mm; KR, NCoRI, CaRH, SN (except c SNH), SnFrB, SCoRO, ne WTR, MP"	"Quercus garryana var. semota"
23	"Leaves 7--11(18) cm, serrate, lateral veins of larger leaves generally 20--28, generally straight and prominent; stipules persistent, > 10 mm, silky-hairy"	"Quercus sadleriana"
23	"Leaves 1--6 cm, entire to dentate, lateral veins of larger leaves generally < 20, generally not straight and prominent; stipules early-deciduous, < 10 mm, not silky-hairy"	24
24	"Shrub to tree generally > 5 m; leaves 2--6 cm, oblong to obovate, entire or +- toothed, adaxially shiny green to dull blue-green"	25
24	"Shrub to small tree generally < 5 m (<i>Quercus berberidifolia</i> sometimes a small tree to 8+ m); leaves 1--5 cm, elliptic to ovate or +- round, variously toothed, adaxially shiny to dull green to dull blue-, yellow-, or gray-green"	26
25	"Shrub, small tree 5--6(10) m; leaf blade (10)20--35(60) mm, adaxially shiny green to dull blue-green, margin entire, dentate, or wavy-dentate"	"Quercus X acutidens"
25	"Tree 5--25 m; leaf blade (20)30--60(80) mm, adaxially blue-green, dull, margin wavy-dentate to generally entire"	"Quercus engelmannii"
26	"Leaf 2-colored, adaxially yellow- to gray-green, abaxially +- white, densely fine-tomentose, hairs obscuring lateral veins"	"Quercus cornelius-mulleri"
26	"Leaf 1--2-colored, adaxially green to gray- or blue-green, abaxially dull light or pale green or gray-green, not densely tomentose, hairs not obscuring lateral veins"	27
27	"Leaf generally oblong to obovate, margin wavy to obtuse-toothed; PR"	"Quercus X acutidens"
27	"Leaf elliptic to ovate or +- round, margin toothed, teeth abruptly pointed to spine-tipped"	28
28	"Acorn cup thin, scales +- tubercled to not; leaf adaxially gray- or blue-green, dull"	29
28	"Acorn cup thick, scales tubercled; leaf adaxially generally green, +- shiny (dull or not in <i>Quercus durata</i>)"	31
29	"Acorn stalk 10--15 mm, nut cylindric-ovoid to elliptic, 12--23 mm, generally yellow-brown, distally obtuse; leaves oblong to elliptic, generally regularly spine-toothed"	"Quercus turbinella"
29	"Acorn stalk 0, nut conic-ovoid, 20--40 mm, generally dark brown, distally acute to +- obtuse; leaves oblong to elliptic or obovate, irregularly toothed, teeth blunt to weakly spiny"	30
30	"Shrub to small tree < 3 m; leaves 1.5--5 cm, toothed but not spine-toothed, adaxially blue- to gray-green"	"Quercus X alvordiana"
30	"Shrub 2--5 m to tree < 7 m; leaves 1.3--2.8 cm, spine-toothed, adaxially gray-green"	"Quercus john-tuckeri"
31	"Leaf adaxially dull, convex, margin often rolled under, obscuring teeth"	32
31	"Leaf adaxially +- shiny, flat to +- wavy, not convex, margin generally not rolled under"	33
32	"Leaf adaxially strongly convex, abaxially short-hairy when young; generally on serpentine, NCoR, n SN, s CCo, SnFrB, SCoR"	"Quercus durata var. durata"
32	"Leaf adaxially +- convex, abaxially densely short-hairy when young; not on serpentine, se WTR, SnGb (s slope)"	"Quercus durata var. gabrielensis"
33	"Leaf abaxially with spreading, 2--6-rayed hairs --- SCo, PR, chaparral or coastal-sage scrub, < 200 m"	"Quercus dumosa"
33	"Leaf abaxially with appressed, 4--10-rayed hairs"	34
34	"Leaf base wedge-shaped or generally truncate or rounded; margin mucro- or spine-toothed; widespread on mainland"	"Quercus berberidifolia"
34	"Leaf base gradually tapered, wedge-shaped, or rounded; margin entire, wavy, or +- toothed, teeth generally mucronate; ChI"	"Quercus pacifica"