| 1. Rays ± 0 (umbels dense, spheric); bractlets 0 or poorly developed |
| |
| 2. Leaf minutely hairy or roughened; bracts conspicuous, fused below; fruit glabrous |
| C. cinerarius |
| 2' Leaf glabrous; bracts 0; fruit hairy |
| |
| C. ripleyi |
| 3' Leaf oblong-ovate, ternate2-pinnately or 2-pinnately dissected |
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| 4. Plant sessile on taproot; fruit wings unequal |
| C. deserticola |
| 4' Plant with leafless stalk above taproot; fruit wings subequal |
| C. globosus |
| 1' Rays ± developed (umbels open to ± dense, not spheric); bractlets evident |
| |
| 5. Plant not woody; corolla purplish; leaf simple to 2-pinnately dissected or compound, lobes, segments, or leaflets wider than linear |
| |
| 6. Bracts 0; leaf round-reniform, ternate |
| C. gilmanii |
| 6' Bracts conspicuous, scarious, veiny; leaf oblong-ovate, 12-pinnate or -ternate |
| |
| 7. Bracts and bractlets greenish or purplish, with many green or purple veins; pedicels < 1 mm |
| C. multinervatus |
| 7' Bracts and bractlets white, with 15 green or white veins; pedicels 38 mm |
| C. purpurascens |
| 5' Plant woody at base; corolla ± yellow or white; leaf finely dissected, segments generally ± linear |
| |
| 8. Leaf finely hairy; corolla white; umbels ± dense |
| C. aboriginum |
| 8' Leaf glabrous; corolla ± yellow; umbels open |
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| 9. Rays generally unequal; calyx lobes persistent; bractlets generally < mature pedicels |
| C. terebinthinus |
| 10. Leaf blade ± as long as wide; Klamath Ranges, High Cascade Range, High Sierra Nevada |
| var. californicus |
| 10' Leaf blade much longer than wide; c East of Sierra Nevada, White and Inyo Mountains |
| var. petraeus |
| 9' Rays subequal; calyx lobes 0; bractlets > mature pedicels |
| C. panamintensis |
| 11. Leaf segments not crowded, 320 mm, flexible |
| var. acutifolius |
| 11' Leaf segments ± crowded, 15 mm, rigid |
| var. panamintensis
|