American Groundnut (Murfreesboro Indigenous Plant Project (MIPP) Guide)

American Groundnut

Apios americana

Summary ⁷

Apios americana, sometimes called the American groundnut, potato bean, hopniss, Indian potato (but not to be confused with other plants sometimes known by the name Indian potato), hodoimo, America-hodoimo, cinnamon vine, or groundnut (but not to be confused with other plants sometimes known by the name groundnut) is a perennial vine that bears edible beans and large edible tubers. Its vine can grow to 1–6 m (3.3–19.7 ft) long, with pinnate leaves 8–15 cm (3.1–5.9 in) long with 5–7 leaflets. The flowers are usually pink, purple, or red-brown, and are produced in dense racemes 7.5–13 cm (3.0–5.1 in) in length. The fruit is a legume (pod) 5–13 cm (2.0–5.1 in) long. Botanically speaking, the tubers are rhizomatous stems, not roots. Its natural range is from Southern Canada (including Ontario, Quebec, and New Brunswick) down through Florida and West as far as the border of Colorado. It is a larval host for the Epargyreus clarus.

Description ⁸

This twining herbaceous vine is up to 10' long, clambering over adjacent shrubs and herbaceous vegetation. The twining stems are light green, terete, and glabrous to minutely pubescent. At intervals along these stems, there occurs alternate compound leaves that are odd-pinnate with 3-7 leaflets (usually 5 leaflets and rarely 3 leaflets). The leaflets are 1½–3½" (4–9 cm.) long and ¾–2¼" (2–5.5 cm.) across; they are lanceolate, oblong-lanceolate, ovate, or broadly ovate in shape with toothless (entire) margins. The upper leaflet surface is medium to dark green and hairless, while the lower leaflet surface is either light green or whitened green and hairless to minutely pubescent. Leaflet venation is pinnate. The leaflets have short light green petiolules (less than ¼" or 6 mm.) that are hairless to minutely pubescent. The petioles and rachises (central stalks) of the compound leaves are light green, narrowly furrowed above, convex below, and hairless to minutely pubescent. The foliage of this vine contains a milky sap. (Source Illinoiswildflowers.org)

Distribution and Habitat ⁸

The native Groundnut (Apios americana) is occasional throughout Illinois. Compared to the past, populations of this vine may have declined because of habitat destruction. It is widely distributed in the eastern half of the United States and southeastern Canada. Habitats include moist to mesic woodlands, typical thickets and sandy thickets, typical sloughs and sandy sloughs, moist prairies and moist meadows, typical seeps and gravelly seeps, banks of streams, and edges of fens. This vine is found in average to high quality natural areas. (Source Illinoiswildflowers.org)

Ecology/Wildlife Use ⁸

The flowers are visited primarily by bees for nectar and, to a lesser extent, pollen. This includes honeybees, bumblebees, leaf-cutting bees (Megachile spp.), and Halictid bees. Leaf-cutting bees are considered the most important cross-pollinators of the flowers. Yellow jackets (Vespula spp.) have also been reported to visit the flowers to a lesser extent (see Robertson, 1929; Bruneau & Anderson, 1994). A claim has been made, on the basis of the structure and coloration of the flowers, that flies are likely to be the primary pollinators of the flowers (Westercamp & Paul, 1993), but this hypothesis has not been substantiated by empirical observation. Several species of ants have been observed to visit the tuberculous extra-floral nectaries on the central stalks of the floral racemes (Harvey, 2009).

Other insects feed on the leaves of Groundnut (Apios americana). This includes the leaf-mining larvae of Pachyschelus schwarzi (a metallic wood-boring beetle), leaf-mining larvae of Cerotoma trifurcata (Bean Leaf Beetle) and Odontota scapularis (Orange-shouldered Leafminer Beetle), and leaf-eating caterpillars of Epargyreus clarus (Silver-spotted Skipper) and Thorybes bathyllus (Southern Cloudywing); see MacRae (1991), Clark et al. (2004), and Barnes (1999). Among vertebrate animals, White-tailed Deer have been observed to feed on the foliage of this vine, and it has been considered a possible source of forage for goats (Morales et al., 2009). Both the seeds and tubers are edible to humans, and they were considered an excellent source of food by both early pioneers and Amerindians. Compared to other commonly eaten tubers and root vegetables, the tubers of Groundnut are unusually high in protein. This vine also provides excellent protective cover for many small to medium-sized mammals, birds, and other fauna. (Source Illinoiswildflowers.org)

Growing Groundnuts ⁸

The preference is light shade to full sun, moist conditions, and loamy, gravelly, or sandy soil containing some organic matter. The root system of this vine fixes atmospheric nitrogen in the soil. This vine may fail to bloom during some years, and when it blooms the flowers often fail to produce seedpods. It can be easily propagated by digging up the tubers of the root system and planting them elsewhere. (Source Illinoiswildflowers.org)

Learn More ⁸

Sources and Credits

(c) John Beetham, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/dendroica/14950819705/
(c) Bob Richmond, some rights reserved (CC BY), http://commons.wikimedia.org/wiki/File:Apios_americana_(3837866496).jpg
(c) birders130, some rights reserved (CC BY-NC), uploaded by birders130
Daderot, no known copyright restrictions (public domain), http://commons.wikimedia.org/wiki/File:Apios_americana_-_Urban_Greening_Botanical_Garden_-_Kiba_Park_-_Koto,_Tokyo,_Japan_-_DSC05388.jpg
(c) Malte, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Apios_americana_tubers.jpg
(c) Judy Gallagher, some rights reserved (CC BY), http://commons.wikimedia.org/wiki/File:American_Groundnut_-_Apios_americana,_Occoquan_Bay_National_Wildlife_Refuge,_Woodbridge,_Virginia_(26058252138).jpg
(c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Apios_americana
(c) Murfreesboro,TN, Natural Resource Division, some rights reserved (CC BY-SA)

More Info

iNat Map

Form	Forb/herb
Light	Full sun, Part sun
Soil moisture	Medium
Site	Meadow, Savanna, Woodland
Bloom period	July, August
Bloom color	Brown, Maroon, Pink
Fruit/seeds/etc.	Pods
Wildlife supported	Insects - larval host, Insects - pollinators, Mammals - large, Mammals - small
Family	Legumes

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