Little Draba verna is a mustard that flowers very early. It tends to cover a lot of sandy and gravelly places, and is also quite frequent in ag fields that have not yet been planted. In the classic "Sand County Almanac," Aldo Leopold called Draba "a small creature that does a small job quickly and well." It is very possible, however, that he was talking about the related Draba reptans, a sand country native.
Photographed in the horseman's campground at Potato Creek State Park, St. Joseph County, Indiana, on March 6, 2012.