General:
Perennial herb from a long creeping rhizome; stems erect, 40-120 cm tall, branched above, smooth, glaucous; milky juice appearing when stems or leaves broken.

Leaves:
Alternate, numerous, unstalked, clasping the stem at the base, egg-shaped to broadly lanceolate, smooth-margined, 2-6 cm long, smooth, glaucous.

Flowers:
Inflorescence a long, terminal, spike-like cluster of numerous short-stalked flowers; corollas bright yellow with a central, orange- to white-hairy patch at the throat, 25-40 mm long including the long straight basal spur, which is shorter than the rest of the corolla, 2-lipped, the upper lip 2-lobed, the lower lip 3-lobed; calyces 5-8 mm long, deeply 5-lobed, the lobes nearly distinct, broadly lanceolate; stamens 4.

Fruits:
Capsules, cylindric-egg-shaped to nearly globe-shaped, 6-8 mm long; seeds numerous, wrinkled and slightly wing-angled, 1-2 mm long.

Source:  The Illustrated Flora of British Columbia