In our species a smooth marsh herb, with creeping rootstock, long-petioled, 3-foliate leaves and white or purplish flowers, in racemes on long lateral scapes.

Creeping rootstocks sometimes a foot long marked by the scars of bases of former petioles. Leaves 3-foliate, petioles sheathing at the base, 2—10 inches long; leaflets oblong or obovate, entire, obtuse at the apex, narrowed to the sessile base, 1½—3 inches long. Flowers half an inch long, pure white or purplish in 10—20-flowered racemes on scape-like naked peduncles; calyx shorter than the corolla which is bearded with white hairs within, giving the flower a feathery appearance.

In open marshes throughout the region, local in distribution; flowering in May and early June.