| | 1. Perennial (biennial?) to subshrubs, rarely flowering first year; pappus scales (6)8–20 per fruit in indistinct series, ± equal; outer corollas radial, not strongly enlarged (sect. Macrocarphus) |
| |
| | 2. Plants not scapose or cespitose or matted; heads (1)3–many per stem; generally below subalpine |
| |
| | 3. Generally per; hairs near stem base thin, cobwebby, gray, thinning with age; basal rosette ± persistent; longest leaf lobes near middle of blade, tips curled |
| C. douglasii var. douglasii |
| | 3' Subshrubs; hairs near stem base dense, felt-like, white, persistent; basal rosette 0 or withering before flowering; longest leaf lobes near base of blade, tips ± flat |
| |
| | 4. Longest phyllaries 10–13 mm, thinly tomentose, not or obscurely glandular; Peninsular Ranges |
| C. parishii |
| | 4' Longest phyllaries 14–17 mm, strongly glandular-hairy, not or scarcely tomentose; Klamath Ranges, Cascade Range |
| C. suffrutescens |
| | 2' Plants ± scapose, cespitose to ± matted; heads 1(–3) per stem; generally subalpine to alpine |
| |
| | 5. Phyllaries ± tomentose, glandless |
| C. alpigena |
| | 5' Phyllaries glandular-hairy |
| |
| | 6. Leaf blades ± ovate, longest lobe near base, tips flat |
| C. nevadensis |
| | 6' Leaf blades linear to elliptic, longest lobe near middle, tips curled to twisted |
| |
| | 7. Largest leaf blades ± widely elliptic, lobes 3–7 pairs, adjacent but not densely crowded |
| C. douglasii var. alpina |
| | 7' Largest leaf blades linear to narrowly elliptic, lobes generally > 9 pairs, densely crowded |
| C. santolinoides |
| | 1' Annual; pappus scales 0 or 4–8 in 1–2 distinct series, outer series (if present) generally << inner; outer corollas often bilateral and strongly enlarged |
| |
| | 8. Lower stem and leaves whitish scaly- or granular-puberulent, appearing ± granular, not cobwebby; largest leaf blades (2)3–4-pinnately lobed, longest lobe near base (sect. Acarphaea) |
| |
| | 9. Tips of longest phyllaries sharp but not acuminate or needle-like, ± flat, green; leaf tips flat; fruit compressed, pappus 0; Transverse Ranges, Peninsular Ranges |
| C. artemisiifolia |
| | 9' Tips of longest phyllaries acuminate, needle-like, cylindric, generally reddish; leaf tips ± cylindric; fruit not compressed, at least the inner with pappus; East of Sierra Nevada, Desert |
| C. carphoclinia |
| | 10. Leaves basal and cauline, < 7 cm; bases of petioles not strongly enlarged |
| var. carphoclinia |
| | 10' Leaves generally basal, longest 7–10 cm; bases of petioles strongly enlarged |
| var. peirsonii |
| | 8' Lower stem and leaves ± cobwebby or glabrous; largest leaf blades entire or 1–2-pinnately lobed, longest lobe generally near middle (sect. Chaenactis) |
| |
| | 11. Corollas white to pinkish, rarely pale yellow |
| |
| | 12. Corollas 9–11 mm, ± 2 × fruit, anthers ± included |
| C. macrantha |
| | 12' Corollas < 9 mm, ± = fruit, anthers exserted |
| |
| | 13. Longest phyllaries 10–18 mm, bases glabrous, tips densely puberulent, glands 0; pappus scales in 2 series; corollas radial; peduncles not glandular |
| C. xantiana |
| | 13' Longest phyllaries < 10(–12) mm, ± uniformly glandular-hairy or cobwebby or glabrous; pappus scales in (0)1 series (rarely 2 in C. stevioides); outer corollas bilateral, expanded; peduncles ± glandular-hairy near heads |
| |
| | 14. Stem base glabrous at flowering time; leaves entire or 1-pinnately lobed, lobes 1–2(5) pairs, well separated; pappus of inner flowers > buds, tips visible; outer phyllaries sharp, becoming glabrous |
| C. fremontii |
| | 14' Stem base at least thinly cobwebby at flowering time; leaves 1–2-pinnately lobed, 1° lobes generally 4–8 pairs, often crowded; pappus < buds, tips hidden; outer phyllaries generally blunt, persistently glandular-hairy or cobwebby |
| C. stevioides |
| | 11' Corollas ± bright to deep yellow |
| C. glabriuscula |
| | 15. Pappus scales in 2 series, scales of outer series (1)3–4, << inner |
| var. heterocarpha |
| | 15' Pappus scales in 1 series |
| |
| | 16. Plants ± scapose, ± densely white-woolly |
| var. lanosa |
| | 16' Plants not scapose, generally thinly gray-cobwebby |
| |
| | 17. Basal leaves strongly fleshy, 2-pinnately lobed; stems ± spreading; South Coast |
| var. orcuttiana |
| | 17' Basal leaves not strongly fleshy, generally 1-pinnately lobed; stems ± erect; not South Coast |
| |
| | 18. Longest phyllaries 5–7 mm, < 2 mm wide, generally ± gray-tomentose at least on midrib, often glandular-hairy; longest pappus < 0.75 × corolla |
| var. glabriuscula |
| | 18' Longest phyllaries 7–9 mm, 2–3 mm wide, green, ± glabrous; longest pappus ± = corolla |
| var. megacephala
|