| | 1. Sepals entire, petal-like, becoming scarious in age; stem disjointing near middle, leaving ring of scarious bracts (sect. Lewisia) |
| |
| | 2. Sepals 2; bracts ovate, 2–4 in ring — flower 10–15 mm |
| L. disepala |
| | 2' Sepals 6–8; bracts awl-like, 5–many in ring |
| L. rediviva |
| | 1' Sepals entire or not, not petal-like; stem not disjointing, bracts generally 2 or alternate on stem, not in ring (sect. Oreobroma) |
| |
| | 3. Sepals 2 but seemingly 4 due to 2 sepal-like bracts immediately below calyx; stems 1-flowered |
| |
| | 4. Sepal margins entire — San Bernardino Mountains, Peninsular Ranges |
| L. brachycalyx |
| | 4' Sepal margins gland-toothed |
| L. kelloggii |
| | 3' Sepals 2, bracts well below; stems 1–many-flowered |
| |
| | 5. Leaves few, cauline; stems from small, spheric corm — flowers 1–10 in loose cluster |
| L. triphylla |
| | 5' Leaves many, mostly in basal rosette; stems from stout, elongated root + caudex |
| |
| | 6. Stem generally 1–2-flowered; flowers generally not or slightly exserted from leaves |
| |
| | 7. Sepal margins gland-toothed; root + caudex elongate, widest at top, tapered or branched below; bracts ± ovate, immediately or well below flowers, margins ± gland-toothed; ± geog restricted — stems often 2-flowered |
| |
| | 8. Petals ± 8 mm, tips irregular, not glandular, not acuminate; root + caudex very stout, rosette dense; bracts in 1–2 irregular pairs, above middle of stem; c&s High Sierra Nevada, East of Sierra Nevada (White Mtns) |
| L. glandulosa |
| | 8' Petals 15–18 mm, tips glandular-acuminate; root + caudex stout, rosette loose; bracts in 1–2 pairs, near middle of stem; n High Sierra Nevada |
| L. longipetala |
| | 7' Sepal margins entire or not, generally not glandular (except rarely in L. pygmaea); root + caudex fusiform, corm-like, or elongate, widest at top, tapered or branched below; bracts generally lanceolate, well below flowers, margins generally entire, not glandular; widespread |
| |
| | 9. Sepal tips ± acute, generally spreading, margins generally ± entire, generally not glandular; flowers 8–15 mm; stem 1-flowered; root + caudex fusiform or corm-like |
| L. nevadensis |
| | 9' Sepal tips ± round, not spreading, margins ± jagged, rarely glandular; flowers 5–10 mm; stem rarely 2-flowered; root + caudex generally elongate, widest at top, tapered or branched below |
| L. pygmaea |
| | 6' Stem generally 2–many-flowered; flowers well exserted from leaves (except sometimes in L. oppositifolia) |
| |
| | 10. Leaf ± linear, flat or cylindric |
| L. leana |
| | 10' Leaf narrowly oblanceolate or wider, flat |
| |
| | 11. Flower generally 6–8 mm — stem 4–7 × leaves, several–many-flowered |
| |
| | 12. Leaves finely to coarsely dentate, ± spoon-shaped, tip round, truncate, or notched — Klamath Ranges, High Cascade Range, n High Sierra Nevada |
| L. cantelovii |
| | 12' Leaves entire, narrowly oblanceolate to obovate, tip acute to blunt |
| |
| | 13. Leaves 3–8 cm, basal; Klamath Ranges |
| L. columbiana |
| | 13' Leaves 10–20 cm, basal and a few cauline; c High Sierra Nevada |
| L. congdonii |
| |
| | 14. Stem 1.5–3 × leaves, 3–11-flowered; pedicels > flowers |
| |
| | 15. Sepal margins jagged-toothed, not glandular; Klamath Ranges |
| L. oppositifolia |
| | 15' Sepal margins gland-toothed; High North Coast Ranges |
| L. stebbinsii |
| | 14' Stem 3–7 × leaves, 12–many-flowered; pedicels generally < flowers; Klamath Ranges, High Cascade Range |
| L. cotyledon |
| | 16. Leaf margins entire; > 1300 m |
| var. cotyledon |
| | 16' Leaf margins not entire; < 2100 m |
| |
| var. heckneri |
| var. howellii
|