General:
Perennial from a strong rhizome and rootstock; stems ascending to erect, several, branched above, 5-27 cm tall, glabrous.
Leaves:
Stem leaves alternate, pimply roughened at the tips, linear to narrowly lanceolate, strongly keeled or nerved on the dorsal surface, broadest above midlength and tapered to the base, usually strongly flattened; lower leaves becoming deciduous, often leaving their midribs attached to the stem.
Flowers:
Inflorescence of terminal, umbrella-shaped clusters; petals 5, yellow, 6-10 mm long, narrowly oblong-lanceolate but not long-pointed, longer than the stamens.
Fruits:
Follicles, more or less spreading.
Source: The Illustrated Flora of British Columbia