A. Thaliana: annual; stem slender, erect; lower leaves stalked, oblong, with a few coarse teeth, upper few, small, sessile; flowers small, white. - Thale-cress. - Banks and waste places. Fl. April.

A. Turrita: biennial; stem stiff, erect; lower leaves stalked, upper sessile, stem-clasping, oblong-lanceolate, slightly toothed; flower small, whitish. - Tower-cress. - Walls, rare. Fl. May.