| | 1. Leaflets 5, 3 near axis tip, lower pair large, stipular in position; stipules gland-like, often not apparent |
| Group 1 |
| | 1' Leaflets 3–15, lowest not stipular in position; stipules as above or not |
| |
| | 2. Stipules scarious or leaflet-like, sometimes fragile and quickly lost; leaflets 3–15, pinnately arranged, often opposite or subopposite |
| Group 2 |
| | 2' Stipules gland-like, bump-like, or conic, often not apparent; leaflets 3–9, pinnately or ± palmately arranged, generally irregularly arrayed on leaf axis |
| |
| | 3. Fruit indehiscent, generally not flat, generally included or moderately exserted from calyx (sometimes conspicuously exserted and curved most of length), generally with curved, 2–3 mm beak; generally per |
| Group 3 |
| | 3' Fruit dehiscent, generally flat, generally almost entirely exserted and straight, generally with straight or curved, 0.5–1.5 mm beak; annual or perennial herb |
| |
| | 4. Annual; fruit generally straight; wings < or ± = keel; stigma glabrous |
| Group 4 |
| | 4' Perennial (except L. strigosus); fruit straight or ± curved; wings generally > keel; stigma nearly glabrous or finely hairy |
| Group 5
|
| | 1. Leaflets 3–5; flower 8–10 mm; plant very small, decumbent; North Coast Ranges |
| L. yollabolliensis |
| | 1' Leaflets (3)5–15; flower generally 8–15 mm; plant various, generally erect or ascending; if leaflets < 5, not of North Coast Ranges |
| |
| | 2. Leaf conspicuously hairy, gray or silvery, with soft, wavy hairs; fruit glabrous |
| L. incanus |
| | 2' Leaf glabrous or hairy, rarely gray or silvery; fruit generally hairy if leaf hairy |
| |
| | 3. Peduncle bract 0 or just below umbel, generally simple or 2–3-parted; fruit 1.5–3 mm wide |
| |
| | 4. Petal claws included to slightly exserted from calyx; plant often hairy |
| L. oblongifolius |
| | 5. Leaflets 3–7, glabrous; corolla 8–9 mm; local, Tulare Co. |
| var. cupreus |
| | 5' Leaflets 7–11, glabrous or hairy; corolla 9–13 mm; more widespread, including Tulare Co. |
| var. oblongifolius |
| | 4' Petal claws clearly exserted from calyx; plant ± glabrous |
| |
| | 6. Corolla wings pink or purple, fading white; bracts generally present and 3-parted |
| L. formosissimus |
| | 6' Corolla wings white; bracts 0 or generally simple |
| L. pinnatus |
| | 3' Peduncle bract generally well below umbel, generally 3–5-parted, sometimes fragile and lost; fruit 3–5 mm wide |
| |
| | 7. Hairs generally persistent, spreading, sometimes glandular; stipules often wide, leaflet-like, persistent and sometimes becoming scarious; corolla pink to red-purple; n&c California |
| L. stipularis |
| | 8. Stem wiry; stipules wide, clasping stem |
| var. ottleyi |
| | 8' Stem often fleshy; stipules narrow or wide, not or slightly clasping stem |
| var. stipularis |
| | 7' Hairs generally nearly 0 or appressed, rarely glandular; stipules scarious, fragile, not leaflet-like, generally some lost; corolla initially white, pink, or yellow-green |
| |
| | 9. Flowers generally 6–10; corolla 10–12 mm, white or pink, becoming striate, darker; pedicel 2–3 mm, slightly longer in fruit; leaflet length generally 2–3 × width; generally n Outer North Coast Ranges |
| L. aboriginus |
| | 9' Flowers generally 12–20; corolla 12–17 mm, yellow-green, becoming dark-blotched; pedicel generally 3–6 mm (> 3 mm at least in fruit); leaflet length generally 1–2.5 × width; widespread, especially inland |
| L. crassifolius |
| | 10. Plant glabrous or strigose; widespread, including n Peninsular Ranges (Riverside Co.) |
| var. crassifolius |
| | 10' Plant soft-hairy; s Peninsular Ranges (San Diego Co.) |
| var. otayensis
|
| | 1. Annual, prostrate or decumbent, sometimes ascending; young growth not conspicuously hairy; flower 3–7 mm; fruit bodies exserted; s South Coast Ranges, Southwestern California, generally s of Los Angeles |
| |
| | 2. Inflorescence ± sessile; s South Coast Ranges, Southwestern California |
| L. hamatus |
| | 2' Inflorescence conspicuously peduncled; s South Coast (San Diego Co.) |
| L. nuttallianus |
| | 1' Perennial or shrub, prostrate to erect; young growth conspicuously hairy if plant blooming 1st year or flowers < 7 mm; fruit bodies included or exserted; widespread, including Southwestern California |
| |
| | 3. Perennial or shrub; Channel Islands |
| |
| | 4. Calyx nearly glabrous or strigose; fruit body soon exserted; leaf green or gray, sparsely or densely strigose or silky |
| L. dendroideus |
| | 5. Leaflets 3, densely strigose or silky, generally gray; n Channel Islands (San Miguel Island) |
| var. veatchii |
| | 5' Leaflets 3–5, finely or sparsely strigose, green; Channel Islands (except San Miguel Island) |
| |
| | 6. Fruit 1–1.5 cm; peduncle bract 0; Channel Islands (except San Miguel, San Clemente islands) |
| var. dendroideus |
| | 6' Fruit 2.5–5 cm; peduncle bract generally present; s Channel Islands (San Clemente Island) |
| var. traskiae |
| | 4' Calyx shaggy-hairy; fruit including (except slowly elongating beak); leaf generally silvery-silky with fine, straight, ultimately wavy or tangled hairs |
| 2 L. argophyllus |
| | 7. Inflorescences peduncled, not crowded; calyx lobes 1.5–2.5 mm; stem decumbent to ascending |
| var. argenteus |
| | 7' Inflorescences ± sessile, densely crowded at stem tip; calyx lobes 2.5–5 mm; stem ascending to erect |
| |
| | 8. Stem erect; leaves overlapping; calyx lobes ± 2.5–3.5 mm; s Channel Islands (San Clemente Island) |
| var. adsurgens |
| | 8' Stem ascending to erect; leaves not overlapping; calyx lobes 2.5–5 mm; n Channel Islands (Santa Cruz Island) |
| var. niveus |
| | 3' Perennial, rarely shrub (except L. scoparius); mainland |
| |
| | 9. Leaflets 3; inflorescence 1–3-flowered, ± sessile |
| |
| | 10. Leaflet 2–5 mm; fruit 6–9 mm; uncommon, se Peninsular Ranges, sw Sonoran Desert |
| L. haydonii |
| | 10' Leaflet 4–12 mm; fruit 10–15 mm; widespread, including Peninsular Ranges |
| |
| | 11. Calyx glabrous (see couplet 15 for vars.) |
| 2 L. scoparius |
| L. procumbens |
| | 12. Corolla 9–12 mm; calyx 4–6 mm, lobes ± = tube; s Sierra Nevada |
| var. jepsonii |
| | 12' Corolla 6–8 mm; calyx 2–3 mm, lobes << tube; not s Sierra Nevada |
| var. procumbens |
| | 9' Leaflets > 3 on some or most leaves; inflorescence 2–15-flowered, sessile or peduncled |
| |
| | 13. Leaflets glabrous or finely strigose, generally green; hairs straight or slightly wavy |
| |
| | 14. Stem generally ascending or erect (some of immediate coast prostrate), bushy-branched, often ± 1 m; stem slightly woody (but green), sparsely leafy; corolla yellow; calyx lobes generally 1–2 mm, not curved outward; coastal and inland |
| 2 L. scoparius |
| | 15. Keel prominent, > wings; flower generally 8–9 mm; generally inland, Southwestern California, Sonoran Desert |
| var. brevialatus |
| | 15' Keel not prominent, ± = wings; flower 7–12 mm; coastal and inland, widespread |
| var. scoparius |
| | 14' Plants prostrate or low-ascending, < 1 m; stem not woody, leafy; corolla pink-white or yellow; calyx lobes generally < 1 mm or curved outward; especially coastal |
| |
| | 16. Calyx lobes slender, some or all curved outward or hooked; corolla generally white to pinkish (to brick-red when dry) |
| L. benthamii |
| | 16' Calyx lobes wide, not curved outward, not hooked; corolla yellow |
| L. junceus |
| | 17. Peduncle 8–25 mm; stem wiry, generally decumbent; fruit body well exserted |
| var. biolettii |
| | 17' Peduncle 1–5 mm; stem generally stout, prostrate to ascending; fruit body slightly exserted |
| var. junceus |
| | 13' Leaflets conspicuously hairy, green, gray, or silvery; hairs straight or wavy |
| |
| | 18. Stem, especially near tip, generally with conspicuous, spreading or obliquely directed, often straight and stiff hairs < 0.5 mm; corolla 4–6 mm; especially coastal California, inland to Desert edge |
| L. heermannii |
| | 19. Corolla generally 4–5 mm; ovary, young fruit generally finely strigose; South Coast, Peninsular Ranges, Desert edge |
| var. heermannii |
| | 19' Corolla generally 5–6 mm; ovary, young fruit generally with spreading hairs; North Coast, Outer North Coast Ranges, Central Coast, Outer South Coast Ranges |
| var. orbicularis |
| | 18' Stem generally strigose or with ± spreading, often wavy hairs generally 0.2–0.4 mm; corolla 5–12 mm; especially inland California |
| |
| | 20. Fruit body exserted; leaflet hairs generally wavy, not obscuring leaflet surface; leaves gray or green |
| L. nevadensis |
| | 21. Flowers generally 3–5 per inflorescence, 6–7 mm, appearing blocky; banner abruptly upcurved 90°; Transverse Ranges, ne Peninsular Ranges |
| var. davidsonii |
| | 21' Flowers generally 5–12 per inflorescence, 5–10 mm, not appearing blocky; banner upcurved 30–90°; not of Transverse Ranges |
| var. nevadensis |
| | 20' Fruit body included or shortly exserted; leaflet hairs at first generally straight, in age tangled and generally obscuring leaflet surface; leaves silky-silvery |
| 2 L. argophyllus |
| | 22. Inflorescence generally < 1 cm wide, 4–8-flowered; corolla 6–10 mm; especially c Sierra Nevada and s |
| var. argophyllus |
| | 22' Inflorescence often 1.5 cm wide, 10–15-flowered; corolla 8–12 mm; n Sierra Nevada |
| var. fremontii
|
| | 1. Flowers generally 1 per leaf axil; peduncle << 1 cm, bracts 0 |
| |
| | 2. Corolla yellow, reddening with age; plant prostrate to low-ascending and calyx lobes 0.8–2 × tube |
| |
| | 3. Calyx lobes 1–2 × tube; fruit generally 3–4 mm wide; plant generally with soft, spreading hairs |
| L. humistratus |
| | 3' Calyx lobes ± 0.8–1.2 × tube; fruit generally 2.3–3 mm wide; plant inconspicuously strigose or with soft, spreading hairs |
| L. wrangelianus |
| | 2' Corolla white, pale yellow, or pink, often darkening with age; plant generally ascending to erect and calyx lobes < 2 × tube, or rarely prostrate and calyx lobes > 2 × tube |
| |
| | 4. Plant generally 1–3 dm; calyx lobes ± 1.5 × tube; common |
| L. denticulatus |
| | 4' Plant < 1 dm; calyx lobes ± 2 × tube; uncommon |
| L. rubriflorus |
| | 1' Flowers 1–several per leaf axil; peduncle generally > 1 cm, generally bracted |
| |
| | 5. Inflorescence generally 2–4-flowered (1st-formed sometimes 1–2-flowered); leaflets 3–7, obovate or ± round, terminal generally largest |
| L. salsuginosus |
| | 6. Corolla 3.5–5 mm, keel > other petals; fruit 1–1.5 cm, becoming narrowed between seeds |
| var. brevivexillus |
| | 6' Corolla 6–10 mm, keel ± = other petals; fruit 1.5–3 cm, not narrowed between seeds |
| var. salsuginosus |
| | 5' Inflorescence generally 1-flowered; leaflets 1–5, lanceolate, elliptic, or obovate, ± equal |
| |
| | 7. Calyx lobes >> tube; leaflets generally 3 (often 1 on upper leaves) |
| L. purshianus |
| | 7' Calyx lobes ± = tube; leaflets 3–9 throughout |
| |
| | 8. Stem erect or ascending; leaf axis not conspicuously flattened; corolla pink or salmon, quickly fading; fruit straight, margin often wavy |
| L. micranthus |
| | 8' Stem prostrate, often mat-forming; leaf axis conspicuously flattened; corolla yellow; fruit curved near tip, margin not wavy |
| L. strigosus
|
| | 1. Annual, generally prostrate and mat-forming; inflorescence generally 1–2-flowered; corolla 5–10 mm; leaf axis flat, ± blade-like; fruit generally curved only at or near tip |
| L. strigosus |
| | 1' Perennial or shrub-like, prostrate (mat-forming or not) to erect; inflorescence 1-9-flowered; corolla 8–25 mm; leaf axis not flat or blade-like; fruit generally straight (sometimes curved throughout, rarely only at or near tip) |
| |
| | 2. Leaf axis including petiole 10–35 mm; leaflets 7–9, generally 1–2 cm, length 1.5–3 × width |
| L. grandiflorus |
| | 3. Plant puberulent or soft-hairy; leaflet generally 1–1.5 cm |
| var. grandiflorus |
| | 3' Plant ± glabrous or puberulent; leaflet generally 1.6–2.2 cm |
| var. macranthus |
| | 2' Leaf axis including petiole 1–8 mm; leaflets 3–5, < 1 cm or length > 3 × width, or both |
| |
| | 4. Shrub-like, ascending, < 1.5 m, finely strigose; corolla 12–22 mm |
| L. rigidus |
| | 4' Perennial, prostrate or low-ascending, < 0.3 m, silvery-silky or gray-puberulent; corolla 8–12 mm |
| L. argyraeus |
| | 5. Stem prostrate, mat-forming; calyx lobes ± 2 mm; San Bernardino Mountains, San Jacinto Mountains, Desert Mountains |
| var. argyraeus |
| | 5' Stem decumbent to low-ascending; calyx lobes 2–3 mm; Desert Mountains |
| |
| | 6. Leaflet oblanceolate to obovate, length ± 3–4 × width; New York Mtns |
| var. multicaulis |
| | 6' Leaflet obovate, length ± 2 × width; Providence Mtns |
| var. notitius
|