| | 1. Flowers 1–20; pedicels long, scapose; bractlets on pedicel 0 (sect. Gymnocaulis) |
| |
| | 2. Flowers generally 5–20; stem (peduncle + inflorescence axis) > 5 cm; bracts > 6; upper pedicels < stem; corolla lobes glabrous to soft-hairy, hairs colorless |
| O. fasciculata |
| | 2' Flowers generally 1–3; stem (peduncle + inflorescence axis) generally < 5 cm; bracts generally < 6; upper pedicels > stem; corolla lobes minutely ciliate, hairs violet |
| O. uniflora |
| | 1' Flowers generally > 20; pedicels 0 or short, not scapose; bractlets on pedicel 2 |
| |
| | 3. Branches at stem base many, slender, yellow; inflorescence open, flowers becoming well separated; calyx generally 4-lobed, cut deepest on upper side; agricultural weed (sect. Trionychon) |
| O. ramosa |
| | 3' Branches at stem base few, stout; inflorescence dense, generally remaining so; calyx 5-lobed, cut ± equally or deepest on lower side; native (sect. Nothaphyllon) |
| |
| | 4. Inflorescence and flowers ± dark purple (lighter in O. pinorum); calyx generally 5–11 mm (–12 mm in O. cooperi) |
| |
| | 5. Calyx divided to base on lower side; hairs of inflorescence and corolla papillate, not glandular; root attachment rounded, coral-like; generally on Adenostoma fasciculatum |
| O. bulbosa |
| | 5' Calyx divided ± equally; most hairs of inflorescence and corolla glandular, not papillate; root attachment not rounded and coral-like (except O. pinorum, sometimes O. cooperi); on various shrubs and herbs |
| |
| | 6. Inflorescence and corolla pale purple-tinged; corolla with a ring of hairs at base of filaments; root attachment rounded, coral-like |
| O. pinorum |
| | 6' Inflorescence and corolla dark purple; corolla lacking ring of hairs; root attachment branched (rarely rounded, coral-like in O. cooperi) |
| |
| | 7. Inflorescence 4–5 cm wide; corolla 18–32 mm, lips 5–10 mm; on herbs of Asteraceae; Desert |
| O. cooperi |
| | 7' Inflorescence 2–3 cm wide; corolla 12–18 mm, lips 3–5 mm; on shrubs, generally in chaparral |
| O. valida |
| | 8. Corolla 14–18 mm, hairy outside, densely so at sinuses, hairs 0.4–0.7 mm; filament base and anther hairy |
| subsp. howellii |
| | 8' Corolla 12–14 mm, puberulent outside, weakly so to glabrous at sinus, hairs ± 0.1 mm; filament base and anther glabrous |
| subsp. valida |
| | 4' Inflorescence and flowers generally buff to pinkish, corolla lips white to pink or lavender with darker veins (purple in O. californica subsp. c.); calyx generally 10–20 mm |
| |
| | 9. Corolla 15–30 mm, lips 4–10 mm, upper erect, lower spreading |
| |
| | 10. Inflorescence 3–4 cm, branched, forming a convex or ± flat-topped cluster; anthers densely hairy throughout; Great Basin Floristic Province, adjacent Cascade Range, High Sierra Nevada, n Desert Mountains |
| O. corymbosa |
| | 10' Inflorescence > 4 cm, of long, generally unbranched, ± raceme-like units; anthers glabrous or hairy along dehisced margin |
| |
| | 11. Upper corolla lobes acute, tips mostly pointed; bracts lanceolate, veins 3–5, inconspicuous; flowers short-pedicelled throughout; California Floristic Province (except c&s Southwestern California) |
| O. vallicola |
| | 11' Upper corolla lobes obtuse, tips rounded to blunt; bracts ± ovate, veins > 5, conspicuous; only lower flowers pedicelled; Southwestern California, Desert |
| O. parishii |
| | 12. Corolla 15–24 mm, lips 4–6 mm; calyx lobes generally 7–10 mm; Central Coast, South Coast, Channel Islands |
| subsp. brachyloba |
| | 12' Corolla 20–25 mm, lips 6–8 mm; calyx lobes 10–16 mm; Transverse Ranges, Peninsular Ranges, Mojave Desert |
| subsp. parishii |
| | 9' Corolla 20–50 mm, lips 10–14 mm, widely flaring (see also O. corymbosa for plants of High Sierra Nevada, Great Basin Floristic Province) |
| O. californica |
| | 13. Corolla lips generally purple; calyx lobes, pedicels, and bracts purplish, drying dark purple; coastal dunes and hills, North Coast, n&c Central Coast |
| subsp. californica |
| | 13' Corolla lips buff to yellowish to pinkish or purple-tinged; calyx lobes, pedicels, and bracts pale to pink-tinged, drying brown; California Floristic Province, inland (except subsp. grandis) |
| |
| | 14. Corolla tube ± stout, > 4 mm wide at constriction, abruptly expanded to form hump-back throat; lips moderately recurved — s High Sierra Nevada, Tehachapi Mountain Area, Transverse Ranges, Peninsular Ranges, s East of Sierra Nevada |
| subsp. feudgei |
| | 14' Corolla tube slender below, < 4 mm at constriction, gradually expanded; lips widely recurved |
| |
| | 15. Corolla 35–50 mm, lower lobes narrowly ovate, > 5 mm wide |
| subsp. grandis |
| | 15' Corolla 20–35 mm, lower lobes narrowly triangular to oblong, < 5 mm wide |
| |
| | 16. Plant 4–10 cm; stem below inflorescence < 5 cm; inflorescence ± flat- or convex-topped cluster < 5 cm; moist or vernally wet places |
| subsp. grayana |
| | 16' Plant 10–35 cm; stem below inflorescence generally > 6 cm; inflorescence elongate, 5–20 cm; dry places |
| subsp. jepsonii
|