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..
Annual tufted glabrous herbs, with pinnatisect leaves, and racemose leafy-bracted yellow flowers. Sepals spreading. Petals narrow, erect, with 10 hypogynous glands at their bases. Silique stalked, very flat, oblong, narrowed at each end. Valves nerveless, thin, finely veined, dehiscent. Style long, slender. Seeds few, in 2 rows in each cell of the pod, orbicular, flat, broadly winged, free from the septum. Cotyledons accumbent. [Greek, moon, from the resemblance of this genus to Lunaria.]
Two or three species, natives of the south-central United States and northern Mexico, the following typical.
Stems simple, numerous, 2'-8' high. Basal leaves 1'-2' long, narrow, 1-2-pinnatifid into numerous oblong dentate or entire segments; stem-leaves similar, smaller; bracts of the raceme pinnatifid, resembling the upper leaves; flowers 3"-4" high, numerous; pedicels 5"-7" long in fruit, spreading or ascending; pod 6"-10" long, 2"-3" broad; style 2" long, very slender.