Berberidaceae, the Barberry Family
Shrubs or herbs; petals 6 or more; stamens 6-18, frequently opening by two terminal lids; pistil 1.
| 1a. Leaves simple — 2. | |
| 1b. Leaves compound — 3. | |
| 2a. Stem shrubby (flowers yellow, in racemes, in spring) | Barberry, Berberis vulgaris. |
| 2b. Stem herbaceous, with a single pair of palmately lobed leaves (4-6 dm. tall; flower white, solitary, terminal, in spring) | May Apple, Podophyllum peltatum. |
| 3a. Leaves all basal; leaflets 2 (2-4 dm. high; the flower-stalks bearing solitary white flowers in spring) | Twin-leaf, Jeffersonia diphylla. |
| 3b. The stem-leaf ternately compound, with numerous leaflets (4-8 dm. high; with yellowish-green clustered flowers in spring) | Blue Cohosh, Caulophyllum thalictroides. |