Erect, annual herb, 5-12 cm tall. Cauline leaves 4.5-6 x 2-3 mm, ovate, 4-5 lobed with truncate base; lobes acuminate, longer than broad, all antrorse (4.4-5 x 2 mm, 4-lobed in aestival and 5.5-6 x 2.5-3 mm, 5-lobed in autumnal form). Racemes lax. Floral leaves similar to cauline leaves but lobes acuminate-aristulate, 3-6 x 3-5 mm (lobes acuminate in aestival and aristulate in autumnal form). Flowers 7-9 mm long, sessile. Calyx 3-5.5 mm long; lobes 1-2.5 x 0.5-1.5 mm, equal; tube 1.3 mm long. Corolla white or pale, dorsally 5-9 mm long; tube 3-4 mm long, externally pubescent on the upper lip and the tube. Upper lip 2-4 mm long. Lower lip 3-5 mm long; lobes oblong-obovate, erose-deeply notched, middle lobe largest 1.5-3 x 1-3 mm, left and right lobes equal or unequal, left and right lobes 1.5-3 x 1-2 mm. Two anthers with subequal awns, two with unequal awns, densely hairy; hairs short, equalling the longer awn. Capsule 5-6.5 x 2-3 mm (c. 5 x 2 mm in aestival and 5.5-6.5 x 2.5-3 mm in autumnal form), oblong-obovate, retuse, equalling the calyces, ciliate at the upper part; cilia stiff. Seeds 4-8 per capsule (4-5 seeds in aestival and 6-8 seeds in autumnal form), oblong, obtuse.