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- Amphicarpaea bracteata
Amphicarpaea bracteata — American hog-peanut
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Facts
American hog-peanut has two forms of flowers, with one type occuring at the top of the plant, and the other underground. The underground flowers are self-fertilizing and don't need to be visited by a pollinator to produce seeds. Needless to say, underground seeds don't often disperse far from the parent plant. However, they are edible, and were widely eaten by Native Americans.
Habitat
Anthropogenic (man-made or disturbed habitats), forests
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Flower petal color
-
- blue to purple
- white
- Leaf type
- the leaves are compound (made up of two or more discrete leaflets
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Number of sepals, petals or tepals
-
- there are five petals, sepals, or tepals in the flower
- there are four petals, sepals, or tepals in the flower
- Fusion of sepals and petals
-
- both the petals and sepals are separate and not fused
- the petals or the sepals are fused into a cup or tube
- Stamen number
- 10
- Stem nodes swollen
- the stem is not swollen at the nodes
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit length
- 15–40 mm
-
Clonal plantlets
- Bulbils
- the plant does not appear to have bulbils
- Bulblets replace flowers
- there are no bulblets where the flowers are located
-
Flowers
- Anther opening
- the anthers have narrow slits or furrows that run lengthwise along the anthers
- Anther spurs
- the anthers do not have spurs on them
- Carpels fused
-
- NA
- the carpel is solitary or (if 2 or more) the carpels are not fused to one another
- Cleistogamous flowers
-
- the plant has some cleistogamous flower
- there are no cleistogamous flowers on the plan
- Corolla morphology
- NA
- Corolla palate
- no
- Corona lobe length
- 0 mm
- Epicalyx
- the flower does not have an epicalyx
- Epicalyx number of parts
- 0
- Filament surface
- the filament is smooth, with no hairs or scales
- Flower description
- the flower has a superior ovary and a hypanthium
- Flower length
- 12–18 mm
- Flower number
- 1–17
- Flower orientation
- the flower bends downwards or hangs downwards
- Flower petal color
-
- blue to purple
- white
- Flower reproductive parts
- the flower has both pollen- and seed-producing parts
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowers sunken into stem
- no
- Form of style
- the style is knob-like at the tip, and unbranched
- Fused stamen clusters
- there are two clusters of fused stamens
- Fusion of sepals and petals
-
- both the petals and sepals are separate and not fused
- the petals or the sepals are fused into a cup or tube
- Horns in hoods (Asclepias)
- NA
- Hypanthium
- the flower has a hypanthium
- Inflorescence one-sided
-
- the flowers are all or nearly all arrayed on one side of the inflorescence axis or branches of the inflorescence
- the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
- Inner tepals (Rumex)
- NA
- Interior flower disk
- the flower has an interior disc
- Length of flower stalk
- 1.5–5 mm
- Length of peduncle
- 10–60 mm
- Marks on petals
- there are no noticeable marks on the petals
- Nectar spur
- the flower has no nectar spurs
- Number of branches in umbel
- 0
- Number of carpels
- 1
- Number of pistils
- 1
- Number of sepals, petals or tepals
-
- there are five petals, sepals, or tepals in the flower
- there are four petals, sepals, or tepals in the flower
- Number of styles
- 1
- Ovary position
- the ovary is above the point of petal and/or sepal attachment
- Perianth shape
- NA
- Petal and sepal arrangement
- the flower includes two cycles of petal- or sepal-like structures
- Petal and sepal colors
-
- blue to purple
- white
- Petal appearance
- the petals are thin and delicate, and pigmented (colored other than green or brown)
- Petal base
- the petal narrows abruptly at the base
- Petal folds or pleats
-
- the petals of the flower do not have folds or plaits
- the petals of the flower have folds or plaits on them
- Petal hairs (Viola)
- NA
- Petal hairs on inner/upper surface
- there are no hairs on the inner/upper petal surface
- Petal length
- 10–15 mm
- Petal length relative to sepals
- the petals are longer than the sepals
- Petal number
- 5
- Petal shape
-
- the petal outline is elliptic (shaped like an ellipse; widest near the middle and tapering at both ends)
- the petal outline is obovate (roughly egg-shaped, but with the widest point above the middle of the leaf blade)
- Petal tips (Cuscuta)
- NA
- Raceme attachment (Veronica)
- NA
- Reproductive system
- all the flowers have both carpels and stamens (synoecious)
- Scales inside corolla
- no
- Sepal and petal color
- the sepals are different from the petals
- Sepal appearance
- the sepals are green or brown, and leaf-like in texture
- Sepal appendages
- the sepals do not have appendages on them
- Sepal appendages (Oenothera)
- NA
- Sepal color
-
- blue to purple
- green to brown
- pink to red
- white
- Sepal length
- 5–6 mm
- Sepal number
- 4–5
- Sepal relative length
- the sepal lobes are shorter than the fused portion
- Sepals fused only to sepals
- the sepals are fused to each other (not other flower parts), at least near their bases
- Spur length
- 0 mm
- Spur number
- NA
- Stamen morphology
- the stamens within each cycle are the same
- Stamen number
- 10
- Stamens fused
- the stamens are attached to one another at or near their bases
- Staminodes
- there are no staminodes on the flower
- Stigma position
- the stigmas are positioned at the tip of the style
- Style petal-like
- the styles are not petal-like
- Umbel flower reproductive parts
- NA
- Upper lip of bilabiate corolla
- NA
-
Fruits or seeds
- Achene relative orientation
- NA
- Achene shape
- NA
- Achene surface (Polygonum)
- NA
- Achene type
- NA
- Berry color
- NA
- Capsule color (Viola)
- NA
- Capsule ribs
- NA
- Capsule splitting
-
- NA
- the capsule splits by two main valves, teeth or pores
- Carpel beak length
- 0 mm
- Fruit (pyxis) dehiscence
- NA
- Fruit cross-section
- the fruit is at least somewhat flattened
- Fruit features (Brassicaceae)
- NA
- Fruit length
- 15–40 mm
- Fruit locules
- one
- Fruit shape
-
- the fruit is flat or strongly compressed
- the fruit is obloid (longer than wide and with rounded ends)
- Fruit type (general)
- the fruit is dry and splits open when ripe
- Fruit type (specific)
- the fruit is a legume (a fruit that splits into two valves, but only has a single carpel; think of a pea pod)
- Fruit width
- 8–10 mm
- Hair type on fruit
- the hairs on the fruits are simple (not branched), don’t have glands, and are not woolly
- Hairs on fruit
- the fruits have hairs on them
- Legumes (Fabaceae)
- the legume has valves that split elastically and coil after they split
- Mericarp length
- 0 mm
- Mericarp segment shape (Desmodium)
- NA
- Other markings on berry
- NA
- Ovary stipe
- the ovary or fruit has a stipe
- Placenta arrangement
- the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
- Rows of seeds in fruit (Brassicaceae)
- NA
- Schizocarpic fruit compression
- NA
- Schizocarpic fruit segments
- 0
- Seed number
- 3–4
- Septum in fruit (Brassicaceae)
- NA
- Wings on fruit
- the fruit does not have wings on it
- prickles on fruits
- the fruits do not have thorn-like defensive structures
-
Glands or sap
- Glands on leaf blade
- the leaf blades do not have glandular dots or scales
- Sap
- the sap is clear and watery
- Sap color
- the sap is clear
-
Growth form
- Growth form
- the plant is a vine (it cannot support its own weight)
- Lifespan
- the plant lives only a single year or less
- Parasitism
- the plant is not parasitic
- Plant color
- the leaves or young stems of the plant are green
- Spines on plant
- the plant has no spines
- Underground organs
- there are only slender roots on the plant
-
Leaves
- Bracteole edges
- NA
- Bracteole length
- 0 mm
- Bracteole number (Apiaceae)
- 0
- Bracteole shape
- NA
- Bracteoles
- there are no bracteoles on the plant
- Bracts in plantain (Plantago)
- NA
- Final leaf segment length (compound lvs only)
- 20–80 mm
- Final leaf segment length to width ratio (compound lvs only)
- 1–1.5
- Final leaf segment width (compound lvs only)
- anything
- Floral bracts
- the flower has one or more bracts associated with it
- Flower bract length
- 2–5 mm
- Hairs on underside of leaf
- the underside of the leaf is fuzzy or hairy
- Hairs on upper side of leaf
- the upper side of the leaf is fuzzy or hairy
- Hooked hairs on underside of leaf
- no
- Inflated hairs on leaf
- the leaf blade does not have inflated hairs on it
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade base
- the leaf has a distinct leaf stalk (petiole)
- Leaf blade base shape
- the base of the leaf blade is rounded
- Leaf blade base symmetry
-
- the leaf blade base is asymmetrical
- the leaf blade base is symmetrical
- Leaf blade bloom
-
- the underside of the leaf has no noticeable bloom
- there is a noticeable powdery or waxy bloom on the underside of the leaf
- Leaf blade edges
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf blade flatness
- the leaf is flat (planar) at the edges
- Leaf blade hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
- Leaf blade primary vein pattern
- the secondary veins branch off at intervals from the primary vein
- Leaf blade shape
-
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- the leaf blade is rhombic (roughly diamond-shaped)
- Leaf blade surface colors
- the upper side of the leaf blade is relatively uniform in color
- Leaf blade texture
- the leaf blade is herbaceous (has a leafy texture)
- Leaf blade vein pattern
- the major veins of the leaf blade branch, but do not rejoin
- Leaf duration
- the leaves drop off in winter (or they whither but persist on the plant)
- Leaf form
- the leaves are green, with an expanded blade and a leaf-like texture
- Leaf hair orientation
- the hairs are flat against the leaf surface, mostly pointing towards the leaf tip
- Leaf shiny
- the upper side of the leaf is dull or slightly shiny
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have leaf stalks
- Leaf stalk attachment to leaf
- the petiole attaches at the basal margin of the leaf blade
- Leaf stalk base
- the petiole base clasps the stem or sheathes the stem
- Leaf teeth and lobes
- the edge of the leaf blade is entire (has no teeth or lobes)
- Leaf tip
-
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- the tip of the leaf blade is acute (sharply pointed)
- Leaf type
- the leaves are compound (made up of two or more discrete leaflets
- Leaf types
- NA
- Leaf variation
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaflet number
- 3
- Leaves per node
- there is one leaf per node along the stem
- Pinnately compound leaf type
- the pinnately compound leaves have a terminal leaflet (and usually have an odd number of leaflets per axis)
- Specific leaf type
- the leaf has a row of two or more lobes on each side of the central axis
- Stipels
- the petiolules have stipels at their bases
- Stipule features
- NA
- Stipule shape
-
- the stipules are lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- the stipules are ovate (widest below the middle and broadly tapering at both ends)
- Stipules
- the plant has stipules
- Teeth per side of leaf blade
- 0
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- forests
- man-made or disturbed habitats
-
Stem, shoot, branch
- Branched tendrils
- NA
- Direction of stem hairs
-
- the hairs are pressed flat against the plant, pointing towards the plant's tip
- the hairs point mostly upwards to outwards
- Hair between stem nodes
- the stem has hairs between the nodes
- Hairs between stem nodes
- the hairs on the stem are plain, without glands or branches, and not tangled
- Hooked hairs on stem between nodes
- no
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Plant height
- Up to 150 cm
- Stem bloom
- there is no powdery or waxy film on the stem
- Stem hair distribution
- the hairs on the stem are distributed more of less uniformly
- Stem nodes swollen
- the stem is not swollen at the nodes
- Stem orientation
- the stems trail at the base, but may turn upwards at the tips
- Stem roughness between nodes
- the stem does not feel rough
- Tendril origin
- NA
- Tendrils
- the plant does not have tendrils
- Wings on stem
- the stem does not have wings on it
Wetland status
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- unranked (S-rank: SNR)
From Flora Novae Angliae dichotomous key
1. Amphicarpaea bracteata (L.) Fern. N
American hog-peanut. Amphicarpaea bracteata (L.) Fern. var. comosa (L.) Fern.; A. comosa (L.) G. Don; A. monoica (L.) Ell.; A. pitcheri Torr. & Gray; Falcata comosa (L.) Kuntze; Glycine bracteata L.; G. comosa L. • CT, MA, ME, NH, RI, VT. Mesic forests, clearings, and shaded roadsides. Amphicarpaea bracteata is sometimes divided into two species— A. bracteata, the slender form with smaller leaflets and white to light purple corollas, and A. comosa, the robust form with larger leaflets and purple corollas. Turner and Fearing (1964) showed that too many intermediate forms exist to regard these as separate taxa.
Native to North America?
Yes
Sometimes confused with
- Phaseolus polystachios:
- flower stalks with bracts that are pointed at the apex, lower petal of flower arching upward in and inward toward center of flower (vs. A. bracteata, with the flower stalks with bracts that are blunt at the apex, lower petal of flower relatively straight).
Synonyms
- Amphicarpaea bracteata var. comosa (L.) Fern.
- Amphicarpaea comosa (L.) G. Don
- Amphicarpaea monoica (L.) Ell.
- Amphicarpaea pitcheri Torr. & Gray
- Falcata comosa (L.) Kuntze
- Glycine bracteata L.
- Glycine comosa L.