Orobanchaceae, the Broom-rape Family
Parasitic plants without green color and with scales in place of leaves; corolla 2-lipped, of united petals; stamens 4, attached to the corolla.
| 1a. Flowers in a widely branching panicle, numerous; growing under beech trees (1-5 dm. high; flowers white and purple, late summer) | Beech Drops, Epifagus virginiana. |
| 1b. Flowers sessile in a dense bracted spike (1-2 dm. high; flowers pale-yellow, early summer) | Squaw-root, Conopholis americana. |
| 1c. Flowers 1-15, each on a long erect naked peduncle (1-2 dm. high; flowers yellowish or pale-violet, spring and summer) (Cancer-root) — 2. | |
| 2a. Stem erect and scaly, 5-10 cm. high | Cancer-root, Orobanche fasciculata. |
| 2b. Stem very short, almost below the surface of the ground, with long erect peduncles | Cancer-root, Orobanche uniflora. |