Papaveraceae, the Poppy Family
Herbs with milky or colored juice, regular flowers, 2 sepals, 4, 6, or 8 petals, numerous stamens, and a 1-celled ovary.
| 1a. Leaves palmately lobed; flower 2.5-5 cm. wide, with 8 petals or more (leaf basal; flower white, in early spring) | Bloodroot, Sanguinaria canadensis. |
| 1b. Leaves pinnately toothed or lobed; flower 7-10 cm. wide, with 4-6 petals (4-8 cm. high; leaves clasping; summer) | Poppy, Papaver somniferum. |
| 1c. Leaves divided pinnately to the mid-rib into several toothed or lobed segments; flower 2.5 cm. broad or less (3-5 cm. high; flowers yellow) — 2. | |
| 2a. Flowers in clusters of 2-4, about 3 cm. wide (spring) | Celandine Poppy, Stylophorum diphyllum. |
| 2b. Flowers in umbels of 3-8, about 1.5 cm. wide | Celandine, Chelidonium majus. |