1	"Nutlet scar on top of +- 0.5 mm angled narrow stalk"	2
1	"Nutlet scar +- sessile, not on narrow stalk, or on short, +- basal peg"	5
2	"Plant cespitose; stem 0.2--0.8 dm, erect; inflorescence +- among leaves"	"Plagiobothrys collinus var. ursinus"
2	"Plant not cespitose; stem 1--4 dm, +- prostrate; inflorescence exceeding leaves"	3
3	"Corolla limb 4--8 mm diam; stem hairs generally +- fine, soft"	"Plagiobothrys collinus var. californicus"
3	"Corolla limb 1--2 mm diam; stem hairs generally coarse, rough"	4
4	"Nutlets 1.5--2 mm; leaf lanceolate, 3--5 mm wide"	"Plagiobothrys collinus var. fulvescens"
4	"Nutlets 1--1.5 mm; leaf linear, 2--2.5 mm wide"	"Plagiobothrys collinus var. gracilis"
5	"Lower cauline leaves alternate, occasionally crowded, occasionally +- opposite, upper alternate; basal rosette present or 0; plant taprooted"	6
5	"Lower cauline leaves opposite, upper generally alternate; basal rosette 0; plant fibrous-rooted, becoming taprooted"	23
6	"Nutlet scar long, narrow, elevated along ridge"	7
6	"Nutlet scar short, +- round (elliptic), sunken below base of ridge"	9
7	"Corolla limb 1--3 mm diam, appendages white, minute; nutlet cobblestone-like, tubercles 0"	"Plagiobothrys jonesii"
7	"Corolla limb 4--10 mm diam, appendages yellow, prominent; nutlet irregularly ribbed, tubercled"	8
8	"Inflorescence coiled in fruit; stems 0.5--1.5 dm, +- equally tall"	"Plagiobothrys kingii var. harknessii"
8	"Inflorescence +- elongate in fruit; stems 1--4 dm, central +- taller"	"Plagiobothrys kingii var. kingii"
9	"Inflorescence coiled in fruit; nutlet scar generally above middle; basal rosette not persistent in fruit"	"Plagiobothrys hispidus"
9	"Inflorescence generally elongate in fruit; nutlet scar at or +- below middle; basal rosette generally present in fruit"	10
10	"Calyx generally circumscissile, lobes generally curved over fruit; stem, abaxial leaf midveins, margins +- red, staining"	11
10	"Calyx generally not circumscissile, lobes generally erect to +- spreading; stem, abaxial leaf midveins, margins green or +- red, staining or not"	13
11	"Bracts 0--few, near base of inflorescence; corolla limb (3)4--9 mm diam; nutlet +- arched"	"Plagiobothrys nothofulvus"
11	"Bracts few--many, +- throughout inflorescence; corolla limb 2--3 mm diam; nutlet generally arched or folded"	12
12	"Nutlets generally 1--2, strongly attached; calyx +- 3 mm, circumscissile in fruit, lobes curved over fruit, dense-spreading-hairy"	"Plagiobothrys arizonicus"
12	"Nutlets generally (2)3--4, weakly attached; calyx 3--5 mm, generally not circumscissile in fruit, lobes erect to occasionally curved over fruit, +- appressed-hairy"	"Plagiobothrys canescens var. catalinensis"
13	"Nutlet scar deep-concave, pit-like"	14
13	"Nutlet scar convex (to shallow-concave)"	15
14	"Bracts 0--few, near base of inflorescence; basal rosette persistent; stem, abaxial leaf midveins, green, not staining; calyx hairs brown"	"Plagiobothrys fulvus var. campestris"
14	"Bracts many, throughout inflorescence; basal rosette short-lived, withered by flowering; stem, abaxial leaf midveins, +- red, staining; calyx hairs tawny to +- white"	"Plagiobothrys infectivus"
15	"Nutlet interspaces between cross-ribs generally wide, flat"	16
15	"Nutlet interspaces between cross-ribs generally narrow, groove-like, sometimes obscure"	17
16	"Lower stem, abaxial leaf midveins +- green, not staining"	"Plagiobothrys canescens var. canescens"
16	"Lower stem, abaxial leaf midveins +- red, staining"	"Plagiobothrys canescens var. catalinensis"
17	"Nutlet +- cross-shaped"	18
17	"Nutlet +- ovate"	19
18	"Inflorescence +- not coiled toward tip, not elongate in fruit; calyx 5--7 mm; nutlet 2--3 mm; flowers generally < 10 per branch"	"Plagiobothrys shastensis"
18	"Inflorescence +- strongly coiled toward tip, elongate in fruit; calyx 3--4(5) mm; nutlet 1--2 mm; flowers generally > 10 per branch"	"Plagiobothrys tenellus"
19	"Calyx hairs minutely hooked at tip; nutlet 1--1.3 mm"	"Plagiobothrys uncinatus"
19	"Calyx hairs not hooked at tip; nutlet 1.5--2.2 mm"	20
20	"Nutlet irregularly papillate, tubercled, cross-ribs 0; se SnFrB (Mount Hamilton Range)"	"Plagiobothrys verrucosus"
20	"Nutlet not papillate or regularly papillate, cross-ribs prominent; c&s SN, SNH, Teh, s SCoRO, SnBr"	21
21	"Nutlet abaxially with +- rows of round, translucent papillae, cross-ribs rounded; nutlet strongly arched, base pointed"	"Plagiobothrys torreyi var. perplexans"
21	"Nutlet abaxially +- without papillae, cross-ribs flat; nutlet +- not arched, base rounded"	22
22	"Stem decumbent to ascending; cauline leaves, bracts many, crowded, ovate to elliptic"	"Plagiobothrys torreyi var. diffusus"
22	"Stem +- erect; cauline leaves, bracts +- few, scattered, +- oblong"	"Plagiobothrys torreyi var. torreyi"
23	"Perennial herb; stem stout; stem, leaf long-soft-spreading-hairy"	24
23	"Annual; stem slender; stem, leaf hairs not simultaneously long, soft, spreading"	25
24	"Nutlet gray, cross-ribs irregular; se CaRH, ne SNH, MP (except Wrn)"	"Plagiobothrys mollis var. mollis"
24	"Nutlet brown, cross-ribs netted; n SnFrB (near Petaluma, s Sonoma Co.)"	"Plagiobothrys mollis var. vestitus"
25	"Flowers generally present near stem base; calyx lobe midvein thickened; stem prostrate"	26
25	"Flowers generally 0 near stem base; calyx lobe midvein occasionally thickened; stem prostrate to erect"	27
26	"Nutlet lance-ovate, dull, attached +- weakly; scar < 20% fruit length, bordered by generally low ridge, funnel-like collar generally 0; lower leaves 3--8 cm"	"Plagiobothrys humistratus"
26	"Nutlet wide-ovate to deltate, shiny, attached strongly; scar 20--35% fruit length, generally bordered by funnel-like collar; lower leaves 1--2 cm"	"Plagiobothrys scriptus"
27	"Nutlet scar 25--60% fruit length, +- deep-concave"	28
27	"Nutlet scar < 20% fruit length, generally +- flat or +- concave (deep-concave in <i>Plagiobothrys diffusus</i>)"	36
28	"Nutlet abaxially with large prickles, barb-tipped or not, or rarely +- 0"	29
28	"Nutlet abaxially generally without large prickles, without barb-tipped projections (minute-bristled)"	32
29	"Nutlet abaxial cross-ribs prominent, creating irregular net-like pattern"	"Plagiobothrys acanthocarpus"
29	"Nutlet abaxial cross-ribs 0 to obscure, net-like pattern 0"	30
30	"Nutlet shiny; prickles few, on ridges abaxially"	"Plagiobothrys austiniae"
30	"Nutlet +- dull; prickles many, throughout abaxially"	31
31	"Nutlet 1.5--3 mm, prickles long, slender, not conic, +- barb-tipped, +- 0 adaxially; scar triangular"	"Plagiobothrys greenei"
31	"Nutlet 1--1.5 mm, prickles short, stout, conic, blunt-tipped, present adaxially; scar narrow-triangular"	"Plagiobothrys hystriculus"
32	"Nutlet scar generally linear, wider near base or not; stem, leaves +- glabrous"	"Plagiobothrys strictus"
32	"Nutlet scar +- pear-shaped or +- triangular; stem, leaves strigose"	33
33	"Nutlet scar < 25% fruit length, concave, flanked by indistinct granular roughness"	"Plagiobothrys trachycarpus"
33	"Nutlet scar 40--60% fruit length, pit-like, flanked by prominent, crowded wrinkles"	34
34	"Calyx lobes +- not longer in fruit; stem prostrate to decumbent; lower leaves 0.5--2.5 cm; corolla limb 1--1.5 mm diam, appendages white; nutlet +- 1 mm, cross-ribs wide, crowded, scar +- pear-shaped"	"Plagiobothrys distantiflorus"
34	"Calyx lobes longer in fruit; stem ascending to erect; lower leaves 4--8 cm; corolla limb > 2 mm diam, appendages yellow; nutlet 1.5--2 mm, cross-ribs narrow, not crowded, scar +- triangular"	35
35	"Corolla limb 5--9 mm diam"	"Plagiobothrys glyptocarpus var. glyptocarpus"
35	"Corolla limb 2--3 mm diam"	"Plagiobothrys glyptocarpus var. modestus"
36	"Nutlet scar basal, generally on short peg; calyx lobe midvein +- stout"	37
36	"Nutlet scar near base or oblique, not on short peg; calyx lobe midvein generally slender"	40
37	"Stem prostrate to decumbent; calyx lobes generally bent, +- same direction, generally upward; nutlet lanceolate"	"Plagiobothrys leptocladus"
37	"Stem ascending to erect; calyx lobes +- bent or straight, erect to +- spreading; nutlet lance-ovate"	38
38	"Calyx base fleshy, lobes oblong to spoon-shaped; pedicel thick, hollow; nutlet adaxially fine- to obscure-granular to smooth, margins with conspicuous, entire border"	"Plagiobothrys glaber"
38	"Calyx base not fleshy, lobes linear to lanceolate; pedicel slender, generally solid; nutlet adaxially coarse-grainy, margins with obscure, not entire border"	39
39	"Corolla limb 2--4 mm diam"	"Plagiobothrys stipitatus var. micranthus"
39	"Corolla limb 5--12 mm diam"	"Plagiobothrys stipitatus var. stipitatus"
40	"Nutlet scar +- linear, slit- or ridge-like"	41
40	"Nutlet scar oblong to triangular or elliptic to ovate, not slit- or ridge-like"	44
41	"Nutlet +- not tubercled, shiny, 1.8--2.5 mm, abaxial cross-ribs 0; corolla limb 2--4 mm diam"	"Plagiobothrys lithocaryus"
41	"Nutlet +- tubercled, dull, 0.8--2 mm, abaxial cross-ribs few--many; corolla limb generally <= 2 mm or > 5 mm diam"	42
42	"Corolla limb 1.5--2 mm diam; pedicel generally 0--1 mm; nutlet abaxially generally +- flat, interspaces narrower than or as wide as cross-ribs"	"Plagiobothrys undulatus"
42	"Corolla limb 5--10 mm diam; pedicel generally 2--15(30) mm; nutlet abaxially convex, interspaces wider than cross-ribs"	43
43	"Leaves of lower pair generally fused at base, +- sheathing stem; stem erect to decumbent, branched from upper axils; corolla limb 6--10 mm diam; pedicels generally > calyx"	"Plagiobothrys chorisianus var. chorisianus"
43	"Leaves of lower pair generally +- not fused at base, not or +- sheathing stem; stem prostrate, branched from lower axils; corolla limb 5--7 mm diam; pedicels generally < calyx"	"Plagiobothrys chorisianus var. hickmanii"
44	"Stem hairs spreading"	45
44	"Stem hairs appressed"	46
45	"Bracts few, near inflorescence base; pedicels 1--3+ mm, slender; calyx +- deciduous; nutlet cross-ribs prominent, scar near base, +- oblong to occasionally narrow-triangular, generally sunken in groove"	"Plagiobothrys parishii"
45	"Bracts +- many, throughout inflorescence; pedicels 0--1 mm, stout; calyx persistent; nutlet cross-ribs low, scar generally oblique, +- ovate, not sunken in groove"	"Plagiobothrys salsus"
46	"Nutlet scar generally oblique at base"	47
46	"Nutlet scar generally above base"	51
47	"Nutlet adaxial ridge, or at least lower part, sunken in groove"	48
47	"Nutlet adaxial ridge not sunken"	49
48	"Nutlet +- ovate; adaxial ridge in wide, well-defined groove; trough around scar generally wide, distinct; abaxial cross-ribs generally irregularly net-like, interspace tubercles generally sparse or small"	"Plagiobothrys reticulatus var. reticulatus"
48	"Nutlet +- oblong-ovate; adaxial ridge in narrow, poorly defined groove; trough around scar generally narrow, +- obscure; abaxial cross-ribs +- few, prominent, scattered, irregular, interspace tubercles generally dense or large"	"Plagiobothrys reticulatus var. rossianorum"
49	"Bracts 0--few, near inflorescence base; calyx base +- 4- ridged in fruit; corolla limb 3--9 mm diam"	"Plagiobothrys tener var. tener"
49	"Bracts many, +- throughout inflorescence (except bracts below inflorescence middle in <i>Plagiobothrys bracteatus</i>); calyx base not ridged in fruit; corolla limb 1--3 mm diam"	50
50	"Nutlet wide-ovate, +- symmetric"	"Plagiobothrys bracteatus"
50	"Nutlet +- oblong-ovate, asymmetric"	"Plagiobothrys cognatus"
51	"Nutlet scar narrow-elliptic to obovate; corolla limb 1--2 mm diam"	52
51	"Nutlet scar +- ovate to triangular; corolla limb 1.5--9 mm diam"	54
52	"Nutlet plump, +- symmetric, sharp-roughened, often also minute-bristled or scabrous, dull; adaxial ridge at +- middle, generally not folded over to 1 side"	"Plagiobothrys hispidulus"
52	"Nutlet +- flat, asymmetric, smooth to rounded-roughened, rarely bristled or scabrous, shiny; adaxial ridge beyond middle, +- folded over to 1 side below"	53
53	"Nutlet wrinkled, tubercled; s NCoRI, CaRH, n&c SNH, sw ScV, GB"	"Plagiobothrys cusickii"
53	"Nutlet not wrinkled, not tubercled; SNE (Deep Springs Lake, ne Inyo Co.)"	"Plagiobothrys nitens"
54	"Bracts many, +- throughout inflorescence; calyx base not ridged in fruit; corolla limb 1.5--5 mm diam"	55
54	"Bracts 0--few, near base of inflorescence; calyx base +- 4-ridged in fruit; corolla limb 3--9 mm diam"	56
55	"Nutlet scar, adjacent ridge in deep trough"	"Plagiobothrys diffusus"
55	"Nutlet scar, adjacent ridge not in trough"	"Plagiobothrys trachycarpus"
56	"Plant fleshy; stem, leaf +- glabrous, glaucous; calyx appressed to stem, lobes erect in fruit; generally on serpentine; NCoRI (Lake, n Napa cos.)"	"Plagiobothrys tener var. subglaber"
56	"Plant not fleshy; stem, leaf sparse-hairy, not glaucous; calyx +- spreading from stem, lobes ascending to +- spreading in fruit; generally not serpentine; NCoR, CaR, w MP"	"Plagiobothrys tener var. tener"