American groundnut

(Apios americana)

Conservation Status
American groundnut
Photo by Luciearl
  IUCN Red List

not listed

     
  NatureServe

N5? - Secure

SNR - Unranked

     
  Minnesota

not listed

     
           
Wetland Indicator Status
     
  Great Plains

FAC - Facultative

     
  Midwest

FACW - Facultative wetland

     
  Northcentral & Northeast

FACW - Facultative wetland

     
           
 
Description
 
 

American groundnut is a native climbing vine with attractive flowers and edible beans and tubers. It is native to the United States east of the Great Plains and to adjacent Canadian provinces. It is cultivated as an ornamental in Europe and as a food in Japan and possibly in South Korea. In Minnesota it is common in the southeast and metro regions, uncommon in the central and north-central regions, and mostly absent from the remainder of the state. It is found in bottomland forests and prairies, on banks of streams and rivers, in fens, marshes, fields, and gardens, on roadsides, and in disturbed areas. It grows in wet to moist areas under light shade to full sun in loamy, gravelly, or sandy soil.

American groundnut is a perennial vine that rises on multiple stems from a long, creeping, horizontal, underground stem (rhizome) and fibrous roots. Fleshy, thickened areas (tubers), modified for food storage, appear evenly spaced along the rhizome. The tubers are ¾ to 2 (2 to 5 cm) long and to ¾ (1 to 2 cm) wide. It the tuber is separated from the plant it will produce another plant (clone). Plants often fail to produce seedpods, and reproduce mostly by cloning.

The stem is slender, round, light green and 3¼ to 10 (1 to 3 m) long. It is usually hairless or sparsely hairy, occasionally densely covered with short, fine, appressed hairs, rarely with longer hairs. It does not produce tendrils. It climbs by spiraling clockwise at the tip around the stem of an nearby plant (twining). When broken, the leaves and stem exude a milky sap.

The leaves are alternate and pinnately divided into usually 5 or 7 leaflets, sometimes just 3 leaflets. The leaf stalk (petiole) is slender and to 2¾ (1.5 to 7.0 cm) long. It may be hairless or hairy. At the base of each petiole there is a pair of small appendages (stipules). Each stipule is to ¼ (4 to 7 mm) long and hair-like.

The leaflets are ¾ to 4 (2 to 10 cm) long, and ¾ to 2 (2 to 6 cm) wide. The leaf blades are egg-shaped or lance-shaped, rounded at the base, and angled or somewhat tapered to a sharp point at the tip. The upper surface is dark green, pinnately veined, and hairless. The lower surface is lighter green and hairless or sparsely to moderately covered with short hairs. The margins are untoothed. The terminal leaflet is on a to 1316 (15 to 30 mm) long leaflet stalk (petiolule) and is symmetric at the base. The lateral leaflets are on 116to (2 to 3 mm) long petiolules and are symmetric or only slightly asymmetric at the base. At the base of each petiolule there is a pair of small appendages (stipels). Each stipel is 132 to 116 (1 to 2 mm) long and inconspicuous. The stipules and stipels are deciduous, dropping off early.

The inflorescence is an unbranched cluster (raceme) of several to many flowers rising from leaf axils. The raceme is ¾ to 2 (2 to 5 cm) long, often short, dense, and cone-shaped. It is on a hairy, ¾ to 2 (2 to 5 cm) long stalk (peduncle). At the base of the raceme there is a 116 to (2 to 3 mm) long modified leaf (bract). At the base of each flower there is a 116 to (2 to 3 mm) long secondary bract (bractlet). The bracts and bractlets are deciduous, dropping off early.

The flowers are about ½ long. There are 5 outer floral leaves (sepals), 5 petals, 10 stamens, and 1 style. The sepals (collectively the calyx) may be light green or colored like the petals. They are united at the base into a broadly bell-shaped, 116 to (2 to 3 mm) long tube then separated into one long and four short lobes. The long lobe is about half as long as the tube. The petals are brownish-red to brownish-purple. They form a butterfly-like corolla, as is typical of plants in the pea family. They are organized into a broad banner petal at the top, two narrow, lateral, wing petals, and between the wings two petals fused into a keel. The banner is strongly concave, broadly notched at the tip, and thickened at the top forming a small hood. The outer surface is usually pale or almost white. The wings are inversely egg-shaped, angled downward, and spreading. The keel is narrow, sickle-shaped, and strongly curved upward. The stamens are equal in length. The stalks (filaments) of nine of the stamens are fused together, the tenth is free. The style is stout and strongly curved or curled. It has a cap-like stigma at the tip.

The fruit is a 1916 to 2 (4 to 6 cm) long, 316 to ¼ (5 to 6 mm) wide seed pod with usually 4 to 6 seeds. It is somewhat flattened and is tapered at the tip. The seeds are dark brown, oblong to almost circular, to 3 16 (4 to 5 mm) long, and (3.5 to 4.0 mm) wide. Fresh fruits are edible but only after being cooked.

 
     
 

Height

 
 

Climbing: 3¼ to 10 (1 to 3 m) long

 
     
 

Flower Color

 
 

Brownish-red to brownish-purple

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Wet to moist. Bottomland forests and prairies, banks of streams and rivers, fens, marshes, fields, gardens, roadsides, and disturbed areas. Light shade to full sun. Loamy, gravelly, or sandy soil.

 
     
 
Ecology
 
 

Flowering

 
 

July to August

 
     
 
Use
 
 

 

 
     
 
Distribution
 
 

Distribution Map

 

Sources

2, 3, 4, 5, 7, 8, 24, 28, 29, 30, 72.

 
  10/13/2020      
         
 

Nativity

 
 

Native

 
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Magnoliopsida (dicots)  
  Subclass Rosidae  
  Superorder Rosanae  
 

Order

Fabales (legumes, milkworts, and allies)  
 

Family

Fabaceae (peas, legumes)  
  Subfamily Faboideae (Papilionoideae)  
  Tribe Phaseoleae  
  Genus Apios (groundnut)  
       
 

Subordinate Taxa

 
       
       
 

Synonyms

 
 

Apios americana var. turrigera

Apios tuberosa

Glycine apios

 
       
 

Common Names

 
 

American groundnut

American potato-bean

America-hodoimo

cinnamon vine

ground-bean

groundnut

hodoimo

hopniss

Indian potato

potato bean

wild bean

 
       

 

 

 

 

 

 

 

 

Glossary

Axil

The upper angle where a branch, stem, leaf stalk, or vein diverges.

 

Bract

Modified leaf at the base of a flower stalk or flower cluster.

 

Bractlet

A small, often secondary bract within an inflorescence; a bract that is borne on a petiole instead of subtending it; bracteole.

 

Filament

On plants: The thread-like stalk of a stamen which supports the anther. On Lepidoptera: One of a pair of long, thin, fleshy extensions extending from the thorax, and sometimes also from the abdomen, of a caterpillar.

 

Peduncle

In angiosperms, the stalk of a single flower or a flower cluster; in club mosses, the stalk of a strobilus or a group of strobili.

 

Petiole

The stalk of a leaf blade or compound leaf that attaches the leaf blade to the stem.

 

Petiolule

The stalk of a leaflet blade on a compound leaf.

 

Pinnate

Having the leaflets of a compound leaf arranged on opposite sides of a common stalk.

 

Raceme

An unbranched, elongated inflorescence with stalked flowers. The flowers mature from the bottom up.

 

Rhizome

A horizontal, usually underground stem. It serves as a reproductive structure, producing roots below and shoots above at the nodes.

 

Stipel

A small, secondary, stipule-like appendage found at the base of a leaflet stalk.

 

Tuber

An underground root (as with dahlias) or stem (as with potatoes), thickened by the accumulation of reserved food (usually starch), which serves for food storage and vegetative propagation.

 

Twining

Growing in a spiral usually around a stem of another plant that serves as support.

       
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Luciearl
       

Found growing on the shore of Gull Lake.

  American groundnut   American groundnut
       
  American groundnut    
       
       
MinnesotaSeasons.com Photos
   

Vine

  American groundnut    
       

Stem

  American groundnut    
       

Leaf

  American groundnut   American groundnut
       
  American groundnut   American groundnut
       
  American groundnut    
       

Flower

  American groundnut   American groundnut
       
  American groundnut    
       

 

Camera

     
Slideshows
   
  Apios americana GROUND NUT
Frank Mayfield
 
  Apios americana GROUND NUT  
     

 

slideshow

       
Visitor Videos
       

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Other Videos
 
  American Groundnut (Apios americana and priceana)
Mountain Gardens
 
   
 
About

Sep 24, 2013

Joe Hollis of Mountain Gardens discusses the American Groundnut.

To learn more, visit http://www.mountaingardensherbs.com/

   
       
  Wild Edibles: Digging up and identifying Apios Americana (Indian Potato)
Thrifty Maine Prepper
 
   
 
About

Sep 7, 2014

My memory card was almost full, so it's a quick vid, but hopefully it helps give people a general idea of what to look for. I am no expert however, so please consult a local expert before eating any wild edibles you find!

And just to prove I am not an expert, I actually ended up getting poison ivy (or maybe poison oak), because I was not paying attention to the surrounding plants while I was digging these up.

This is on my little bug out island in Maine.

   
       
  Edible Plants: Groundnut
Blanche Cybele Derby
 
   
 
About

Aug 4, 2014

Groundnut aka Hopniss ("Apios americana") is a plant native to North America .Try it instead of, or with, potatoes and other vegetables.

   
       

 

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Luciearl
8/30/2020

Location: Fairview Twp, Cass County

Found growing on the shore of Gull Lake.

American groundnut


     
     
 
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Created: 10/13/2020

Last Updated:

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