Online Virtual Flora of Wisconsin

Lathyrus palustris L.

Family: Fabaceae

marsh pea, marsh vetchling, slender-stem pea-vine

[Lathyrus myrtifolius Muhl. ex Willd., more...]

Merel R. Black

University of Wisconsin - Madison (WIS-VP)

Open Interactive Map

Etymology: Lathyrus: from the Greek lathyros, an old name for "pea"
Plants: climbing, perennial, 1'-4' long forb; stems often winged
Leaves: pinnately-divided into 2-4 pairs of leaflets with a tendril at the end; asymmetrical, sharp-pointed, leaf-like appendages at the base
Flowers: purple and white, 5-parted, 3/4" long; inflorescence a long-stalked cluster (raceme) of 2-6 stalked flowers; blooms June-July
Fruits: long pod
Habitat: wet to moist; meadows, shores, marshes
Hazardous: Careful, this plant is hazardous!
Conservation Status: Native

Marshes, fens, alder thickets, shrub carrs, lakeshores, riverbanks, streambanks and pond margins, bogs, sedge meadows, wet prairies, beaches, wet fields; marly lagoons, cobble beaches, and dune swales along Lake Michigan, tamarack swamps, floodplain forests of silver maple-river birch-elm and silver maple-ash, moist forests of hemlock-ash-maple, white cedar-black ash-spruce, and bur oak-spruce-balsam fir. A highly variable species; plants with winged stems will sometimes have stipules as large as those of L. ochroleucus. They can be told apart by their bluish to pink or purple flowers and the often sharply acute basal lobes on the stipules. Lathyrus ochroleucus has cream flowers and stipules with rounded, toothed lobes. Found mostly in the eastern half of the state but rare in the southern part of the Driftless Area. Mostly absent from the Northern Highlands and sporadic throughout the northwestern counties.