Perennials; (forming pincushion-like, pulvinate mounds, caudex woody, to 1.5 cm diam., buried, much-branched, covered with persistent leaves); puberulent. Stems simple from base (caudex branches), erect to ascending, unbranched distally, 0.05-0.2 dm. Basal leaves rosulate; petiole undifferentiated; blade obovate, 2.5-5 cm × 15-25(-35) mm, margins entire, (ciliolate), apex deeply 3-lobed (lobes ovate to suborbicular, margins entire). Cauline leaves absent. Racemes slightly elongated in fruit, (2-7-fruited); rachis puberulent, trichomes straight, cylindrical. Fruiting pedicels suberect to ascending, often straight, (terete), 2-4.5 × 0.2-0.3 mm, puberulent throughout. Flowers: sepals (tardily deciduous), obovate, 1.3-4 × 0.8-1.1 mm; petals pale yellow or creamy white, spatulate, 1.8-2.9 × 0.8-1.2 mm, claw 0.8-1.1 mm; stamens 6; filaments 1.4-2 mm, (glabrous); anthers 1.4-2 mm. Fruits ovate, 2-4.2 × 1.5-3 mm, often apically winged, apical notch 0.1-0.2 mm deep; valves thin, smooth, not veined, glabrous; style (0.4-) 0.6-1(-1.2) mm, exserted beyond apical notch. Seeds oblong, 1-2 × 0.8-1 mm.

Flowering May-Jun. Gypsum knolls, tufa mounds around hotsprings, quartzite gravel, barren areas with shale and chalky soil, gravelly hillsides, white calcareous soils; 1500-2200 m; Nev., Utah.

Lepidium nanum is most common in Nevada and is known in Utah from collections in Tooele County.