| | 1. Lower leaves pinnately compound, leaflets 9–15 |
| |
| | 2. Lower leaflets deeply dissected; sepal tip bristly; petal base ciliate |
| E. cicutarium |
| | 2' Lower leaflets ± toothed; sepal tip glabrous; petals glabrous |
| E. moschatum |
| | 1' Lower leaves simple, entire to pinnately divided, lobes or divisions < 9 |
| |
| | 3. Leaf blade deeply 7–9-lobed or -divided |
| |
| | 4. Stem coarsely hairy; fruit body 8–11 mm, pit atop body generally subtended by 2 deep furrows |
| E. botrys |
| | 4' Stem glandular-hairy; fruit body 6–8 mm, pit atop body subtended by 1 shallow furrow |
| E. brachycarpum |
| | 3' Leaf blade crenate to 3–5-divided |
| |
| | 5. Leaf < 4 cm; sepals canescent; petals unequal |
| E. texanum |
| | 5' Leaf > 4 cm; sepals ± hairy but not canescent; petals equal |
| |
| | 6. Leaf blade deeply 3–5-divided, divisions wedge-shaped; petals blue |
| E. cygnorum |
| | 6' Leaf blade entire to shallowly lobed; petals white to purple |
| |
| | 7. Leaves basal; blade reniform, ± entire |
| E. macrophyllum |
| | 7' Leaves basal and cauline; blade ovate, crenate |
| E. malacoides
|