in G. Bentham,Plantas Hartwegianas imprimis Mexicanas. 341. 1857.
Herbs, to 35 cm. Leaves erect; petiole 3–15 cm; blade absent or narrowly lanceolate to ovate, 3–9 × 0.5–3 cm, margins entire. Inflorescences racemes, rarely panicles; scapes erect or ascending; bracts broadly ovatelanceolate, thin, scarious. Flowers 12–22 mm wide; sepals persistent, green, oblong or ovate, somewhat hooded, 4–5 mm; petals white with yellow patch near base, rarely pink, broadly cuneate, rhombic, 6–10 mm, erose distally; stamens 2–3 mm, 2 in front of each petal; pistils 6–10 in single ring on receptacle; ovules 1; styles erect in anthesis, soon spreading radially, elongate, stout. Fruits horned by enlargement of style, ribbed on angles, with prominent angular shoulder and depressed flat faces, 0.5 × 3–5.5 mm; beak 3–6 mm.
Phenology: Flowering late summer.
Habitat: Vernal pools, margins of intermittent streams, or on mud
Elevation: 100–1700 m
Calif., Idaho, Nev., Oreg.
"thin" is not a number.