Fumariaceae, the Fumitory Family
Herbs with watery juice, compound or dissected leaves, and irregular flowers; sepals 2, small; petals 4, in two pairs, and one or both of the outer pair spurred at the base; stamens 6.
| 1a. Both outer petals spurred or sack-like at the base — 2. | |
| 1b. One outer petal spurred or sack-like at the base — 4. | |
| 2a. A climbing vine with flowers in panicles (white or pinkish flowers in summer) | Climbing Fumitory, Adlumia fungosa. |
| 2b. Low herbs (2-4 cm.) with basal leaves and white or pinkish flowers in racemes (early spring) — 3. | |
| 3a. Spurs of the corolla triangular, divergent | Dutchman’s Breeches, Dicentra cucullaria. |
| 3b. Spurs of the corolla short and rounded | Squirrel Corn, Dicentra canadensis. |
| 4a. Flowers about 5 mm. long, pink-purple tipped with red (3-8 dm. high; summer) | Fumitory, Fumaria officinalis. |
| 4b. Flowers 10 mm. long or more, yellow, at least at the tip (2-6 dm. high) (Corydalis) — 5. | |
| 5a. Flowers yellow throughout (spring) | Corydalis, Corydalis aurea. |
| 5b. Flowers pink, tipped with yellow (summer). | Corydalis, Corydalis sempervirens. |