| | 1. Calyx ribs strap-shaped, wider at base than membrane; lobes of bract tip 7–many; fruit dehiscing from base upward, not to tip (sect. Mitracarpium) |
| |
| | 2. Axis of upper leaves and often of bracts wider above middle |
| |
| | 3. Central stem < or = branches; axis white-hairy |
| N. jaredii |
| | 3' Central stem generally > branches; axis puberulent |
| |
| | 4. Bracts generally hairy and puberulent, axis of inner bracts wider below middle, generally not above |
| 2 N. pubescens |
| | 4' Bracts puberulent, axis wider below and above middle |
| N. setiloba |
| | 2' Axis of upper leaves and bracts linear |
| |
| | 5. Corolla throat lacking spots |
| |
| | 6. Corolla bright blue with purple throat |
| 2 N. pubescens |
| | 6' Corolla yellow or white (sometimes lobe tips blue) |
| |
| | 7. Inflorescence puberulent, slightly or not hairy; corolla lobes 4 |
| N. cotulifolia |
| | 7' Inflorescence densely white-hairy, corolla lobes generally 5 |
| N. eriocephala |
| | 5' Corolla throat with purple or brown spots |
| |
| | 8. Corolla lobes purple; fruit 8-valved |
| N. jepsonii |
| | 8' Corolla lobes white or yellow; fruit 4-valved |
| |
| | 9. Corolla white; fruit 1–2-seeded |
| N. heterandra |
| | 9' Corolla yellow; fruit 2–9-seeded |
| N. nigelliformis |
| | 10. Corolla 12–16 mm; branches ascending; herbage dark green |
| subsp. nigelliformis |
| | 10' Corolla 9–11 mm; branches decumbent; herbage gray-green |
| subsp. radians |
| | 1' Calyx ribs tapered, narrower at base than membrane; lobes of bract tip generally 0–few; fruit dehiscing from tip downward (if dehiscing upward, then only when wet) |
| |
| | 11. Plant generally not glandular; seeds stuck together until wet; fruit translucent, sticking to seeds, opening at base when wet (sect. Navarretia) |
| |
| | 12. Axis of inner bracts concave-expanded at base; corolla lobes ovate |
| |
| | 13. Bract tips with 3 spreading spines; corolla lobes with 1 vein entering base; stigmas 2 |
| N. intertexta |
| | 14. Bracts and calyces densely white-hairy; plant erect, loosely branched, 8–28 cm |
| subsp. intertexta |
| | 14' Bracts and calyces sparsely white-hairy; plant spreading, densely branched, < 10 cm |
| subsp. propinqua |
| | 13' Bract tips without 3 spreading spines; corolla lobes with 3 veins entering base; stigmas 3 |
| |
| | 15. Calyx and bracts glabrous; bract tips entire; calyx lobes entire |
| N. subuligera |
| | 15' Calyx and bracts appressed-hairy; bract tips many-lobed; calyx lobes toothed |
| N. tagetina |
| | 12' Axis of inner bracts widely membranous-winged at base, not concave-expanded; corolla lobes linear or narrowly ovate (N. leucocephala group) |
| |
| | 16. Mature inflorescence a head (flowers sessile); plants prostrate |
| |
| | 17. Corolla 12–21 mm, tube long-exserted; involucral leaves lobed near base |
| N. myersii |
| | 17' Corolla 7–9 mm, tube slightly exserted; involucral leaves with many lobes above and below |
| N. prostrata |
| | 16' Mature inflorescence a dense cyme (flowers subsessile or short-pedicelled); plants generally not prostrate |
| |
| | 18. Calyx tube hairy; seeds 5–25; s California; Baja California |
| N. fossalis |
| | 18' Calyx tube glabrous or slightly hairy; seeds 2–7; n&c California |
| N. leucocephala |
| | 19. Corolla tube exserted, throat 2–3 mm wide, lobes narrowly ovate |
| subsp. leucocephala |
| | 19' Corolla tube included, throat 1–2 mm wide, lobes linear |
| |
| | 20. Inflorescence 2–20-flowered; outer bracts generally with 3–5 entire or forked lobes |
| subsp. pauciflora |
| | 20' Inflorescence 10–60-flowered; outer bracts generally with 7 or more 3–4-branched lobes |
| |
| | 21. Corolla < or = calyx; some calyx lobes generally toothed; Cascade Range, Sierra Nevada, Great Basin Floristic Province |
| subsp. minima |
| | 21' Corolla = or > calyx; calyx lobes generally entire; North Coast Ranges, w Sacramento Valley |
| |
| | 22. Stem generally erect, branches ascending; corolla white |
| subsp. bakeri |
| | 22' Stem low, branches spreading; corolla blue — rare |
| subsp. plieantha |
| | 11' Plant generally glandular; seeds not stuck together; fruit opaque, not sticking to seeds, dehiscing downward from tip to base |
| |
| | 23. Outer bracts with short or linear axis and linear lobes, terminal lobe ± as wide as laterals (sect. Masonia) |
| |
| | 24. Bracts pinnately lobed |
| |
| | 25. Corolla yellow; plant puberulent, not glandular-hairy |
| N. breweri |
| | 25' Corolla lavender; plant puberulent and glandular-hairy |
| N. peninsularis |
| | 24' Bracts palmately lobed |
| |
| | 26. Corolla 8–10 mm; stamens and style exserted |
| N. prolifera |
| subsp. lutea |
| | 27' Corolla lobes blue to purple |
| subsp. prolifera |
| | 26' Corolla 4–7 mm; stamens and style included |
| N. divaricata |
| | 28. Corolla white with pink lobes; longest bract 5–10 mm |
| subsp. divaricata |
| | 28' Corolla purple; longest bract 7–20 mm |
| subsp. vividior |
| | 23' Outer bracts with broad axis and tapered lobes (if bracts palmate then middle lobe much wider than laterals) (sect. Aegochloa) |
| |
| | 29. Tip of outer bracts 3-lobed, often hooked |
| |
| | 30. Leaf lobes generally pointed tipward (basal lobes spreading); bract lobes pointed tipward, tips not hooked |
| N. atractyloides |
| | 30' Leaf and bract lobes spreading; bract tips generally hooked |
| N. hamata |
| | 31. Corolla pale colored; bracts hairy, not glandular, 3 lobes of hook equal |
| subsp. parviloba |
| | 31' Corolla bright colored; bracts gland-dotted or glandular-hairy, 3 lobes of hook generally unequal |
| |
| | 32. Corolla tube included, throat wide |
| subsp. hamata |
| | 32' Corolla tube exserted, throat narrow |
| subsp. leptantha |
| | 29' Tip of outer bracts neither 3-lobed nor hooked |
| |
| | 33. Bract bases not concave, lobes many, generally forked on back; stamens attached in tube |
| |
| | 34. Corolla light blue, 5–7 mm; outer bracts with middle lobe ovate-acuminate |
| N. mellita |
| | 34' Corolla dark blue, 9–12 mm; outer bracts with middle lobe lanceolate, long-tapered |
| N. squarrosa |
| | 33' Bracts or their bases concave, lobes few, not forked on back; stamens attached in throat |
| |
| | 35. Outer bracts much longer than wide |
| |
| | 36. Inflorescence leaves thread-like, lobed only at base |
| N. filicaulis |
| | 36' Inflorescence leaves strap-shaped or lanceolate, lobed at base and above |
| N. viscidula |
| | 35' Outer bracts little longer than wide |
| |
| | 37. Corolla > calyx, purple; stamens, style exserted |
| N. heterodoxa |
| | 37' Corolla = calyx, lavender or white; stamens, style included |
| N. rosulata
|