Stems: spines at nodes (1-)2-3(-7); internodal prickles absent or sparse. Leaf blades 0.7-1.1 cm, base deeply cordate, surfaces finely pubescent and glandular-puberulent, more glandular abaxially, lobes cuneate-rounded, margins with 3-7 unequal crenate dentations. Peduncles 1-3 mm. Pedicels 1-3(-4) mm, glabrous. Flowers: hypanthium greenish white to white or pinkish, broadly campanulate to rotate, 1.4-3 mm, glabrous; sepals pale greenish white or with slight reddish tinge, ovate-oblong, 1-3.3 mm, apex rounded, glabrous or sparsely hairy; petals white, broadly obovate-rhombic to flabelliform-reniform, 1-1.6 mm, base shortly, broadly clawed, apex truncate, slightly erose; filaments 0.5- 1 mm; styles 2.5-3.3 mm. Flowering Jun-Jul. Limestone cliffs and talus; 900-2900 m; Idaho, Mont., Nev.