C. flavula , the yellow corydalis, is a small plant of six to twelve inches with pale yellow flowers. If you are not familiar with Corydalis then think of your grandmother's Bleeding Hearts for they both have similar foliage. It sets prolific seed and I would not recommend bringing this species into the garden unless you have a large relaxed woodland setting. It will get into, under and in-between every other plant in the garden. C. sempervirens , the pink corydalis, is our second species.
Flowers are the typical four petals with two being much longer than others.
There is a sack-like spur on one of the two larger petals. Corydalis is Greek for Lark, referring to the spur on both flower and bird's foot. Both of our native species have gray-green leaves, typically compound and divided. Height is a bit larger, coming in at just over a foot. Habit is more open and lax when the species gets much beyond that height.