Geraniaceae, the Geranium Family
Herbs, with deeply lobed or divided leaves; flowers regular, with 5 sepals, 5 petals, 5 or 10 stamens, and a 5-celled ovary.
| 1a. Anthers 5 (spreading or ascending plants, 2-4 dm. high; flowers pink or purple, spring and summer) — 2. | |
| 1b. Anthers 10 — 3. | |
| 2a. Leaves pinnately dissected | Stork’s-bill, Erodium cicutarium. |
| 2b. Leaves palmately divided into cuneate lobes | Crane’s-bill, Geranium pusillum. |
| 3a. Leaves ternately divided, the lobes pinnatifid (2-4 dm. high; flowers purple, late spring and summer) | Herb Robert, Geranium robertianum. |
| 3b. Leaves palmately 3-11-lobed — 4. | |
| 4a. Petals 12 mm. long or more (3-6 dm. high; flowers pale purple, spring) | Wild Geranium, Geranium maculatum. |
| 4b. Petals less than 10 mm. long (Crane’s-bill) — 5. | |
| 5a. Seed-bearing portion of the pistil smooth, glabrous or nearly so (low spreading plant; flowers purple, late spring and summer) | Crane’s-bill, Geranium columbinum. |
| 5b. Seed-bearing portion of the pistil transversely wrinkled (widely branching. 1-3 dm. tall; flowers purple, summer) | Crane’s-bill, Geranium molle. |
| 5c. Seed-bearing portion of the pistil pubescent (widely branching. 1-5 dm. tall) — 6. | |
| 6a. Leaves divided almost to the base (flowers pinkish or white, spring and summer) — 7. | |
| 6b. Leaves divided one-half to two-thirds the way to the base (flowers purple, summer) | Crane’s-bill, Geranium rotundifolium. |
| 7a. Petals white or pale pink; flowers in compact clusters | Crane’s-bill, Geranium carolinianum. |
| 7b. Petals pink-purple; flowers in loose clusters | Crane’s-bill, Geranium bicknellii. |