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Native Plant Trust: Go Botany Discover thousands of New England plants

Phaseolus coccineus — scarlet bean

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Facts

Scarlet bean is native to montane Central America, where it has been domesticated for over two thousand years, although the wild type still grows in the region. Cultivars are widely grown for their ornamental flowers and edible legumes. It occasionally escapes in eastern North America including Massachusetts.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
Flower petal color
  • blue to purple
  • pink to red
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
Stamen number
10
Fruit type (general)
the fruit is dry and splits open when ripe
Show all characteristics
  • 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
    Calyx symmetry
    there is only one way to evenly divide the calyx (the calyx is bilaterally symmetrical)
    Carpels fused
    • NA
    • the carpel is solitary or (if 2 or more) the carpels are not fused to one another
    Cleistogamous flowers
    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 petal color
    • blue to purple
    • pink to red
    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
    Horns in hoods (Asclepias)
    NA
    Hypanthium
    the flower has a hypanthium
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inner tepals (Rumex)
    NA
    Length of flower stalk
    10–25 mm
    Nectar spur
    the flower has no nectar spurs
    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
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes two cycles of petal- or sepal-like structures
    Petal and sepal colors
    • blue to purple
    • pink to red
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    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 hairs on the inner/upper petal surface
    Petal length
    15–20 mm
    Petal number
    5
    Petal tips (Cuscuta)
    NA
    Petal width
    8–15 mm
    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 appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal length
    5–7 mm
    Sepal number
    5
    Sepal relative length
    the sepal lobes are shorter than the fused portion
    Sepal uniformity
    all the sepals are about the same size
    Sepals fused only to sepals
    the sepals are fused to each other (not other flower parts), at least near their bases
    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
    • the stigmas are positioned on the inner surface 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
    Fruit (pyxis) dehiscence
    NA
    Fruit features (Brassicaceae)
    NA
    Fruit locules
    one
    Fruit shape
    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)
    Hairs on fruit
    the fruits have hairs on them
    Legumes (Fabaceae)
    the legume has none of the mentioned special features
    Mericarp length
    0 mm
    Mericarp segment shape (Desmodium)
    NA
    Other markings on berry
    NA
    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
    At least 2
    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
    Plants darken when dry
    no
    Spines on plant
    the plant has no spines
  • Leaves

    Bracteole number (Apiaceae)
    0
    Bracteoles
    the plant has bracteoles between the primary bracts and the flowers
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length (compound lvs only)
    40–100 mm
    Final leaf segment length to width ratio (compound lvs only)
    1–1.8
    Floral bracts
    the flower has one or more bracts associated with it
    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
    yes
    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 cordate (heart-shaped, has rounded lobes at the base)
    • the base of the leaf blade is rounded
    Leaf blade base symmetry
    the leaf blade base is asymmetrical
    Leaf blade edges
    the edge of the leaf blade is entire (has no teeth or lobes)
    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)
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade veins
    the leaf blade has one main vein running from the base towards the tip (it may or may not have secondary veins)
    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 spines
    there are no spines on the leaf edges
    Leaf stalk
    the leaves have leaf stalks
    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 variation
    the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
    Leaflet number
    1–3
    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
    Stipules
    the plant has stipules
    Teeth per side of leaf blade
    0
  • Place

    Habitat
    terrestrial
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Scent

    Plant odor
    the plant does not have much of a smell
  • Stem, shoot, branch

    Branched tendrils
    NA
    Flowering stem cross-section
    • the flowering stem has strong or sharp angles, but is not square
    • the flowering stem is circular, or with lots of small angles so that it is roughly circular
    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
    yes
    Plant height
    100–400 cm
    Stem orientation
    • the stems are upright or angled outwards
    • the stems trail at the base, but may turn upwards at the tips
    Stem spacing
    the plant is solitary, or a few plants are growing together
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils

Wetland status

Not classified

In New England

Distribution

Connecticut
absent
Maine
absent
Massachusetts
present
New Hampshire
absent
Rhode Island
absent
Vermont
absent

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
not applicable (S-rank: SNA)

From Flora Novae Angliae dichotomous key

1.  Phaseolus coccineus L. E

scarlet bean. MA. Fields, gardens, dumps.

Native to North America?

No

Sometimes confused with

Phaseolus vulgaris:
corolla 10–15 mm long, pink-purple to nearly white, inflorescence often not exceeding the subtending leaves, and plants upright or twining (vs. P. coccineus, with the corolla 15–20 mm long, red or bright purple or rarely light purple, inflorescence usually exserted beyond the subtending leaves, and plants twining).

Family

Fabaceae

Genus

Phaseolus