This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Corydalis flavula Raf.; DC. Prodr. 1: 129. 1824. Capnoides flavulum Kuntze, Rev. Gen. Pl. 14. 1891.
Slender, glabrous, diffuse or ascending, 6'-14' high, freely branching. Lower leaves slender-petioled, the upper nearly sessile, all finely dissected into linear or oblong, sometimes cuneate, acute or obtuse segments; pedicels very slender; bracts conspicuous, broadly oblong, acute or acuminate, 3"-4" long; spur ¥' long, rounded; outer petals slightly longer than the inner, yellow, sharp-pointed; crest dentate; pods torulose, drooping or spreading; seeds sharp-margined, finely reticulated.
Ed. 5, 62. 1867. Corydalis micrantha A. Gray, Coult. Bot. Gaz. II: 189.
Habit and foliage nearly as in the preceding species, the ultimate leaf segments generally slightly broader. Flowers similar, the crest entire; or sometimes cleistogamous and minute, spurless and slightly or not at all crested; pods ascending, short-pedi-celled, torulose; seeds obtuse-margined, smooth, shining.
In woods, Minnesota to Missouri, Kansas, Texas, Virginia and Florida. Feb.-April.
Capnoides aureum Kuntze, Rev. Gen. Pl. 14. 1891.
Glabrous, 6'-14' high, diffuse, branching. Leaves all but the uppermost petioled, finely dissected into oblong obovate or cuneate segments, mainly broader than those of related species; flowers 6" long, bright yellow; spur one-half the length of the body of the corolla, or more, rounded; outer petals keeled, not crested; pedicels short, slender; pods spreading or pendulous, torulose, especially when dry; seeds obtuse-margined, shining, obscurely reticulated.