Boechera stricta (Graham) Al-Shehbaz
Family: Brassicaceae
Drummond's rock-cress
Boechera stricta image
from USDA Plants website  
Etymology: Arabis: a Greek word used for "mustard" or "cress," and the Greek word for Arabia, perhaps referring to the ability of these plants to grow in rocky or sandy soils (?)
Plants: erect, biennial/perennial forb, mostly hairless
Leaves: stem leaves stalkless, lance-like to oblong, lobed at the base
Flowers: white, 4-parted, 1/3"-1/2" wide; inflorescence a short cluster (raceme) of stalked flowers; blooms May-Aug.
Fruits: long, thin, flat, straight pods pointing upward on a smooth stalk; seeds in 2 rows
Conservation Status: Native