Online Virtual Flora of Wisconsin - Amphicarpaea bracteata

Amphicarpaea bracteata (L.) Fernald

Family: Fabaceae

American hog-peanut, hog-peanut

[Amphicarpa bracteata (L.) Fernald, more...]

Christopher Noll

University of Wisconsin - Madison (WIS-VP)

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Etymology: Amphicarpaea: Greek for "two-seeded" referring to two kinds of seed
Plants: twining, annual, 6"-60" long, herbaceous vine
Leaves: long stalked, divided into 3 broadly oval leaflets
Flowers: white to lavender, 5-parted, 1/2" long, stalked; inflorescence a loose cluster from the leaf axil; blooms Aug.-Sept.
Fruits: flat, oblong pod pointed at both ends, usually with 3-seeded
Habitat: moderate moisture to wet; woods, forests, meadows, prairies
Conservation Status: Native

Found in a wide variety of dry to mesic forests including oak, oak-pine, oak-hickory, maple-oak, maple-basswood, maple-beech-hemlock, aspen, pine, balsam fir-spruce-paper birch, maple-pine; in floodplain forests or swampy woods of ash-basswood-elm, maple-birch-hemlock, white cedar-balsam fir-hemlock, and maple-elm. Also found on marsh borders, along streambanks, lakeshores, Lake Michigan sand dunes, in sedge meadows and shrub carr, mesic prairies, thickets, wooded cliffs and bluffs, and along roadsides, trails, logging roads, and railroad tracks. This is an unusual plant, being an annual of forest borders and understories. It has a complicated reproductive system, producing aerial chasmogamous and cleistogamous flowers as well as subterranean cleistogamous flowers; a thorough overview of these is given by Schnee & Waller (1986). Much has been written about the variability of this species and the potential for cryptic species within it. Variety comosa (L.) Fern. differs from the typical variety in having stems and petioles with abundant hairs and pubescent fruits. Variety bracteata is less pubescent with fruits that are glabrous or glabrate. Due to the large overlap in range and morphology, it doesn’t seem worth recognizing any infraspecific taxa. Found throughout the state but mostly absent from the Northern Highlands.