Rhizomatous perennial. Stems erect, 5–30 cm. Herbage glabrous to strigose, glandular. Leaves all cauline, opposite, petiolate; the blades simple, 1–8 cm long, ovate, entire to serrate. Inflorescence terminal and axillary, minutely bracteate racemes. Flowers white, 2-merous; hypanthium ca. 0.5 mm long; sepals 1–2 mm long, reflexed; petals 2-lobed, 1–2 mm long; stamens 2. Fruit an obovoid 1-celled capsule, 1–2 mm long, with hooked hairs; seed solitary (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)
Montana plants are subspecies alpina
(Asch & Magnus) Raven.
Moist forest, thickets, often in moderately disturbed soil; valleys to subalpine (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX)