Annual herb from a fibrous root; stems decumbent (taller plants) to erect (smaller plants), several to many, unbranched to few branched, glabrous, 2-5 (15) cm tall.
Basal leaves pinnate with 3-13 toothed or lobed segments, the segments oblanceolate, 4-10 mm long, sometimes again toothed, stalked, the stalks about as long as the leaves, glabrous, stem leaves similar, few.
Inflorescence of single, terminal flowers on stalks about as long as the leaves; petals usually 4, white to yellowish, egg-shaped, 4-5 mm long; sepals usually 4, egg-shaped, sharp-pointed, with 2 rows of hairs at the base, 3-4 mm long.
Nutlets, 3-4, rarely 1, somewhat cone-shaped, 2.8-3.2 mm long, greyish-green to brown, with small protrusions on the tops and sides. LINACEAE 1. Plants perennials; sepals rounded at the tips, not fringed; leaves linear, 3-veined only at the bases L. lewisii1. Plants annuals, biennials or perennials; sepals tapered to narrow points, inner ones usually fringed; leaves linear-lanceolate, 3-veined at least 1/2 their length. 2. Plants annuals; flower stalks 20-25 mm long; petals 10-14 mm long; capsules 10-14 mm long, or more; seeds with a short, blunt beak L. usitatissimum2. Plants biennials or perennials; flower stalks 5-18 mm long; petals 8-10 mm long; capsules 5-6 mm long; seeds beakless L. bienne
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
When in flower, Limnanthes macounii can be easily identified by its pinnate leaves and four-part flowers, but when lacking flowers it can be confused with four other taxa: Lepidium virginianum ssp. menziesii, Cardamine spp., Nemophila parviflora, and Nemophila pedunculata (Ceska and Ceska 2003). L. macounii can be distinguished from the first two species by the lack of a tap root and the presence of totally glabrous leaves. It differs from Nemophila species in having glabrous pinnate leaves (vs. non-glabrous, pinnatisect leaves).
Source: British Columbia Conservation Data Centre