Amphicarpaea bracteata (L.) Fernald var. bracteata
Amphicarpaea monoica (L.) Elliott
American hog-peanut, ground bean
American hog-peanut is native to eastern North America. It inhabits woodlands, thickets, low wooded areas along streams, and moist slopes.
Plants: Plants look like low-lying mats of foliage, but at close quarters they are actually thin-stemmed vines 24-96" (60-243 cm) long. Small tendrils hang onto nearby plants. Stems are less than ¹/₃₂" (1 mm) thick, light green to reddish green, and covered with thin flattened (appressed) hairs.
Leaves: Leaves are alternate, in groups of three delicate leaflets, along twining stems. The central leaflet, called the terminal leaflet, is up to 2½" (6.3 cm) long about about the same width. Leaflets are ovate to ovate-rhombic, with sharp tips. The other two leaflets tend to be a bit smaller. Leaflets are mostly hairless on top, and usually hairier and lighter in color below.
Flowers: Pink to white to pale lavender, ½-¾" (1.3-1.9 cm) long. Open flowers are cross-pollinated, while closed flowers are self-pollinating. Flowers are tubular in shape, with an upright-facing banner, 2 side wings, and a keel. The edges of the banners are often folded backward. Closed flowers may occur above or below ground. Open flowers occur in compact clusters of 2-15 along the vine. They appear from August to September.
Fruits: Open flowers form flat pods, ½-1½" (1.5-4 cm) long, pointed at both ends, containing 1-4 seeds. When mature, the dried pods burst to disperse the seeds. Closed flowers produce a pod containing a single seed.
Edibility: Below-ground pear-shaped seeds are “sweet and delicious,” eaten raw or cooked, tasting like shelled garden beans. Seeds from above-ground seed pods are said by some sources to be inedible, and by others to be edible after cooking.
Amphicarpaea bracteata var. bracteata at Illinois Wildflowers
Amphicarpaea bracteata var. bracteata on Wikipedia
Amphicarpaea bracteata var. bracteata on gobotany.nativeplanttrust.org
Amphicarpaea bracteata var. bracteata on Plants for a Future
Amphicarpaea bracteata var. bracteata at Minnesota Wildflowers
Amphicarpaea bracteata var. bracteata description by Thomas H. Kent, last updated 22 Aug 2020.