| 1. Leaves uniformly green, not mottled |
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| 2. Perianth white with yellow base; stigma ± entire |
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| 3. Perianth segments 1020 mm, without sac-like folds at base |
| E. purpurascens |
| 3' Perianth segments 1835 mm, inner with small sac-like folds at base |
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| 4. Perianth segments < 1/3 yellow; leaves 617 cm; flowers 13; Klamath Ranges, High Cascade Range |
| E. klamathense |
| 4' Perianth segments 1/31/2 yellow; leaves 1035 cm; flowers 18; s High Sierra Nevada |
| E. pusaterii |
| 2' Perianth yellow; stigma entire or lobed |
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| 5. Perianth segments 1528 mm; style and filaments yellow; stigma entire or with lobes < 1 mm; flowers 110 |
| E. pluriflorum |
| 5' Perianth segments 2035 mm; style and filaments white; stigma entire or with slender, recurved, 24 mm lobes; flowers 15 |
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| 6. Fresh perianth segments with narrow, pale zone at base; stigma lobes 24 mm; Klamath Ranges, North Coast Ranges |
| E. grandiflorum |
| 6' Fresh perianth segments lacking pale zone at base; stigma entire or with lobes < 1 mm; c Sierra Nevada Foothills |
| E. tuolumnense |
| 1' Leaves irregularly mottled with brown or white |
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| 7. Filaments flat at base, generally > 1.5 mm wide; stigma lobes 46 mm |
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| 8. Perianth segments pink with yellow base |
| E. revolutum |
| 8' Perianth segments white with yellow base |
| E. oregonum |
| 7' Filaments < 0.8 mm wide; stigma entire to lobed |
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| 9. Perianth violet to pink with dark purple base |
| E. hendersonii |
| 9' Perianth ± white with yellow base |
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| 10. Style 410 mm; anthers yellow, white, or cream |
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| 11. Anthers white to cream; style ± straight; bulblets 0 |
| E. citrinum |
| 11' Anthers yellow; style ± bent; bulblets 0 or sessile |
| E. helenae |
| 10' Style 1015 mm; anthers white to cream |
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| 12. Flower-stalk (when flowers > 1) branched well above leaves; bulblets 0 |
| E. californicum |
| 12' Flower-stalk (when flowers > 1) branched near ground level; bulblets produced from long, slender rhizomes |
| E. multiscapoideum
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