OXALIDACEAE, the Wood Sorrel Family
Herbs, with alternate or basal compound leaves with 3 reverse heart-shaped leaflets; sepals, petals, and styles each 5; stamens 10. (Wood Sorrel)
| 1a. Leaves all basal; flowers white to pink-purple (1-2 dm. high; late spring) [— 2.] | |
| 1b. Stem-leaves present; flowers yellow (1-5 dm. high; spring and summer) [— 3.] | |
| 2a. Flower-stalks bearing a single flower | Wood Sorrel, Oxalis acetosella. |
| 2b. Flower-stalks bearing an umbel of several flowers | Wood Sorrel, Oxalis violacea. |
| 3a. Stem prostrate and creeping Wood Sorrel, Oxalis repens. | |
| 3b. Stem erect or ascending [— 4.] | |
| 4a. Pedicels with spreading pubescence | Wood Sorrel, Oxalis corniculata. |
| 4b. Pedicels with appressed pubescence | Wood Sorrel, Oxalis stricta. |
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. |
RUTACEAE, the Rue Family
Shrubs or low trees, with compound leaves frequently dotted with translucent glands; flowers small, greenish-white, with 3-5 sepals, petals, and stamens.
| 1a. Leaflets 5-9; stems thorny | Prickly Ash, Zanthoxylum americanum. |
| 1b. Leaflets 3; stems not thorny | Hop Tree, Ptelea trifoliata. |