1 "Flowers generally in head-like clusters; plant generally rosetted or tufted; NW, CaR, SN, MP, n SNE --- hypanthium bractlets < 0.5 mm wide; hypanthium generally 2--5 mm wide; lower pedicel often reflexed in fruit; > 300 m" 2 1 "Flowers generally either in +- flat-topped clusters or inflorescence open; plant often matted; CA-FP, W&I" 8 2 "Leaflets 2--5 per side, entire to +- 3-toothed; petal linear to obovate; fruit 1.5--2 mm; 300--2500 m" 3 2 "Leaflets 3--15 per side, > 3-toothed; petal +- wedge-shaped; fruit 1--1.8 mm; > 950 m" 5 3 "Stem densely glandular above, ascending to erect; petal generally 2.5--4 mm, generally widely obovate --- nw KR" "Horkelia congesta var. nemorosa" 3 "Stem +- glabrous to sparsely glandular above, often decumbent; petal 1.5--4 mm, linear to widely oblanceolate" 4 4 "Petal +- widely oblanceolate, often < sepal; hypanthium 2.5--5 mm wide, inner wall hairy (except in NCoRH); KR, NCoR, n SNH" "Horkelia tridentata var. flavescens" 4 "Petal generally narrow-oblanceolate, generally >= sepal; hypanthium generally 2--3.5 mm wide, inner wall generally glabrous; CaR, SN, MP" "Horkelia tridentata var. tridentata" 5 "Leaflets generally divided +- 3/4 to base, generally 8--15 per side, +- crowded; filament generally < 0.5 mm, generally wider than long --- s CaRH" "Horkelia fusca var. tenella" 5 "Leaflets generally toothed <= 1/2 to base, generally 4--8 per side, +- separated; filament often > 0.5 mm, generally longer than wide" 6 6 "Petal 4--6 mm; leaflets generally 10--20 mm, toothed < 1/4 to base, generally +- obovate; anther +- 0.6 mm; style 1--1.5 mm; fruit +- 1.8 mm; Wrn" "Horkelia fusca var. pseudocapitata" 6 "Petal 2--4 mm; leaflets generally 5--15 mm, toothed 1/4--1/2 to base, +- round to wedge-shaped; anther +- 0.4 mm; style +- 1 mm; fruit 1--1.2 mm; n California (except Wrn), SNH" 7 7 "Leaflets +- gray-hairy, narrow-wedge-shaped; CaR, MP" "Horkelia fusca var. brownii" 7 "Leaflets green, wedge-shaped to round; e KR, SNH, n SNE" "Horkelia fusca var. parviflora" 8 "Pedicel +- recurved in fruit; inflorescence open, often +- 1-sided" 9 8 "Pedicel erect in fruit; inflorescence open or dense, not 1-sided" 10 9 "Petal 4--7 mm; leaflets toothed 1/4 to midrib; pistils generally 20--50; n&c SNF (especially Ione Formation)" "Horkelia parryi" 9 "Petal 2--3 mm; leaflets lobed 1/2 to 3/4 to base; pistils < 5; SnBr" "Horkelia wilderae" 10 "Filament generally < 0.5 mm, generally wider than long; style +- 1 mm --- petal +- wedge-shaped; s CaRH" "Horkelia fusca var. tenella" 10 "Filament >= 0.5 mm, generally longer than wide; style 1--4 mm" 11 11 "Plant generally rosetted from simple or few-branched caudex; resinous odor weak; leaflets generally < 10-lobed; fruit >= 2 mm; often +- serpentine clay" 12 11 "Plant generally tufted to matted from a few- to many-branched caudex; resinous odor strong; leaflets often > 10-toothed or -lobed; fruit often < 2 mm; generally non-serpentine" 15 12 "Leaflets 5--10 per side, 5--25 mm, lobed > 3/4 to base; stem base hairs 2--3 mm; inflorescence open to dense; hypanthium 3.5--5 mm wide; petal +- obovate, cream; pistils 5--15; style 2.5--4 mm" 13 12 "Leaflets +- 15 per side, 2--10 mm, generally lobed +- 1/2 to base; stem base hairs +- 1 mm; inflorescence open; hypanthium 2--3 mm wide; petal obcordate, often pink-tinged; pistils 2--6; style +- 1.5--2 mm" 14 13 "Leaflets +- gray, lobes 2--5, 1--3 mm wide; petal 2--4 mm wide; pedicels nonglandular" "Horkelia daucifolia var. daucifolia" 13 "Leaflets green, lobes 5--15, < 1 mm wide; petal 4--8 mm wide; pedicels glandular" "Horkelia daucifolia var. indicta" 14 "Stipules of basal leaves pinnately divided; leaves +- green, 5--15 cm" "Horkelia howellii" 14 "Stipules of basal leaves entire or forked; leaves silvery, 3--10 cm" "Horkelia sericata" 15 "Leaflets pinnately veined, oblong to obovate, +- evenly > 10-toothed --- hypanthium width 4--8 mm, > 2 × length, bractlets +- 2--3 mm wide; CW, SW" 16 15 "Leaflets +- palmately veined at base, wedge-shaped or +- round-ovate, +- unevenly few- to many-toothed or -lobed" 19 16 "Leaflets 1--3 per side, < distinct terminal leaflet, teeth generally double, generally > 20; petal +- round, +- 5 mm wide; 400--1300 m; PR" "Horkelia truncata" 16 "Leaflets 5--12 per side, +- = generally indistinct terminal leaflet, teeth generally single, +- 10--15; petal obovate or narrower, 1.5--4 mm wide; < 870 m; CCo, SCoRO, SCo" 17 17 "Hairs +- all glandular; inflorescence open; hypanthium inner rim +- glabrous; filament base generally 0.5--2 mm wide" "Horkelia cuneata var. puberula" 17 "Hairs mostly glandless; inflorescence open to dense; hypanthium inner rim generally hairy; filament base 0.5--1 mm wide" 18 18 "Inflorescence generally +- open; hairs +- spreading, +- dense; glands +- obvious" "Horkelia cuneata var. cuneata" 18 "Inflorescence dense to +- open; hairs ascending to appressed, dense; glands hidden, if any" "Horkelia cuneata var. sericea" 19 "Hypanthium width 4--10 mm, 1--2 × length, bractlets ovate, generally +- 2 mm wide, +- = sepal; leaflets round to ovate, 5--60 mm, generally +- separated, generally > 20-toothed or -lobed; stem +- leafy; fruit +- 1 mm" 20 19 "Hypanthium width generally < 6 mm, generally 2+ × length, bractlets lanceolate to ovate, <= 2 mm wide, < sepal; leaflets round to wedge-shaped, generally < 15 mm, often crowded, < 20-toothed or -lobed; stem leaves few, +- reduced; fruit > 1 mm" 22 20 "Leaflets 3--5 per side, generally unlobed, 15--60 mm, elliptic to ovate --- hypanthium inner wall glabrous; sepal not red-mottled; style 2--3 mm; CW" "Horkelia californica var. frondosa" 20 "Leaflets 4--9 per side, +- lobed, 5--40 mm, ovate to round" 21 21 "Leaflets generally few-lobed +- 1/2 to base, 10--40 mm; sepal red-mottled inside; hypanthium bractlets generally toothed; hypanthium inner wall +- hairy; filament generally 1.5--3 mm; style generally 3--4 mm; NCo, CCo" "Horkelia californica var. californica" 21 "Leaflets lobed 1/2--3/4 to base, 5--25 mm; sepal not red-mottled; hypanthium bractlets generally entire; hypanthium inner wall glabrous; filament generally 0.5--1.5 mm; style generally 2--3 mm; NCoR, c&s SN, SnFrB, SnBr" "Horkelia californica var. elata" 22 "Stem < 25 cm; hypanthium bractlets generally < 0.5 mm wide; leaves 2--10 cm; fruit 1.5--2.5 mm; > 2000 m; KR, s SNH, W&I" 23 22 "Stem 10--70 cm; hypanthium bractlets generally >= 0.5 mm wide; leaves 3--20 cm; fruit 1.5--2 mm; < 2800 m; NCo, NCoR, CW, SW" 25 23 "Hypanthium densely hairy on inner rim; sepal 3.5--6 mm, 2+ × hypanthium length; longer hairs +- 1 mm, soft --- ne KR" "Horkelia hendersonii" 23 "Hypanthium +- hairy on inner wall; sepal generally 2--4 mm, < 2 × hypanthium length; longer hairs +- 0.5 mm, stiff" 24 24 "Leaflets generally 10--14 per side, generally 2.5--4 mm; pistils 10--20; W&I" "Horkelia hispidula" 24 "Leaflets generally 4--6 per side, generally 3.5--8 mm; pistils 5--12; s SNH" "Horkelia tularensis" 25 "Stem decumbent to ascending, generally 10--30 cm; plant matted, odor strong; inflorescence +- dense; leaves generally 4--10 cm; leaflets generally 5--10 per side, +- crowded --- hairs dense; NCo, CCo" "Horkelia marinensis" 25 "Stem ascending to erect, 10--70 cm; plant tufted or matted, odor strong or not; inflorescence generally +- open; leaves generally 3--20 cm; leaflets 6--16 per side, separated or crowded" 26 26 "Hypanthium bractlets 1--2 mm wide, lanceolate to ovate; anther +- 1 mm --- hypanthium generally 3--6 mm wide; stem hairs spreading; SCoRO" "Horkelia yadonii" 26 "Hypanthium bractlets generally 0.5--1 mm wide, linear or elliptic to lanceolate; anther 0.5--1 mm" 27 27 "Stem and petiole hairs generally spreading; plant often green" 28 27 "Stem and petiole hairs generally ascending to appressed; plant generally +- gray --- hypanthium inner wall +- hairy" 29 28 "Leaflets toothed +- 1/3 to base; hypanthium inner wall glabrous; PR" "Horkelia clevelandii var. clevelandii" 28 "Leaflets divided > 1/2 to base, lobes linear to oblanceolate; hypanthium inner wall +- hairy; NCo, NCoRO, SnFrB" "Horkelia tenuiloba" 29 "Leaf 3--8 cm; pistils generally 10--20; style 1--2 mm; NCoRI" "Horkelia bolanderi" 29 "Leaf 4--20 cm; pistils generally 20--50; style generally 2--3 mm; TR" "Horkelia rydbergii"