Flowers of Draba nemorosa have 4 small yellow petals and 4 pale green or yellow-green sepals. Leaves are simple and unlobed and though they may appear entire at first glance, close examination will usually reveal a few small, distant teeth partially masked by the dense pubescence of branched or stellate hairs. There are always basal rosette leaves and usually at least 1 or 2 cauline leaves low on the flowering stem. The cauline leaves do not clasp the stem. Plants are frequently 4 -10 cm tall, perhaps up to 15 cm by some accounts. Leaves are often 5-8 (-10) mm long in the populations I have seen.
Draba nemorosa is a small, annual plant that grows on dry, sunny sites of low productivity. It begins to flower very early, in early- to mid-April, and is usually done flowering by early May, after which time it is much harder to see. It appears to be an ephemeral species taking advantage of the spring moisture on sites that become intolerably dry later in the season.
Draba nemorosa is known from only a few sites in Wisconsin. The Marinette and Brown County populations in northeastern Wisconsin are still extant. Vouchers for Sauk and LaCrosse Counties are both in excess of 40 years old and the current status of those populations is unknown.