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..
Low tufted mostly stellate-pubescent herbs, with scapose or leafy stems, simple leaves, and mainly racemose flowers. Silicles elliptic, oblong or linear, flat, few to many-seeded, glabrous or pubescent. Stigma nearly entire. Seeds wingless, arranged in 2 rows in each cell of the pod, numerous; valves dehiscent, nerveless; cotyledons accumbent. [Greek name for some plant of this family.]
Species about 175, mainly natives of the north temperate and arctic regions, a few in southern South America. Besides the following, some 30 others are natives of western North America. Type species: Draba verna L.
Petals deeply 2-cleft.
Petals entire, toothed, or emarginate.
Flowering stems scapose,leafy only below.
Plants annual, not arctic.
Leaves entire, obovate or oblong.
Leaves dentate, cuneate.
Low arctic perennials.
Leaves pilose-ciliate or glabrous.
Flowering stems leafy throughout up to the inflorescence.
Leaves remotely low-dentate or entire.
Basal leaves loosely pubescent, ciliate.
Basal leaves densely stellate-canescent.
Fruiting pedicels divergent.
Fruiting pedicels nearly erect.
Leaves sharply dentate.
Pods oblong, 1"-2" long.
Pods linear or lanceolate, 3"-6" long.
Annual; pods 3"-4" long; pedicels divaricately spreading.
Perennial; pods 4"-7" long; pedicels erect.