Dioscorea villosa — wild yam

Characteristics

• Clonal plantlets

  Axillary bulblets

  there are no bulblets being produced in axils

• Flowers

  Anther attachment

  the anther is attached by its base to the filament

  Anther color

  the anthers show no hint of a pink, reddish or purplish tint

  Bulblets replace flowers

  there are no bulblets where the flowers are located

  Carpels fused

  the carpels are fused (the number of carpels equals the number of locules)

  Flower bract length

  1–3 mm

  Flower bracts

  there are bracts associated with the flower

  Flower number

  1–18

  Flower orientation

  • the flowers curve or droop downwards
  • the flowers point upward or spread or curve outward

  Flower petal color

  • green to brown
  • white

  Flower petal length

  0.5–2 mm

  Flower shape

  • the flower has a funnel-shaped corolla tube
  • the flower is bell-shaped
  • the flower is flattened or platter-shaped

  Flower symmetry

  there are two or more ways to evenly divide the flower (the flower is radially symmetrical)

  Form of style

  the style is branched above the base

  Fringed petal edges

  the petals are not fringed

  Hairs on flower stalk

  the flower stalk has no hairs on it

  Inflorescence hair glands

  NA

  Inflorescence length

  20–300 mm

  Inflorescence type

  • the flowers grow out of the axil (point where a branch or leaf is attached to the main stem)
  • the inflorescence has only one flower on it
  • the inflorescence is a dichasial cyme (an axis with a terminal flower, below it a pair of branches, each with a terminal flower, these branches may in turn have a pair of branches and so on)
  • the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)

  Length of flower stalk

  At least 0 mm

  Length of peduncle

  20–300 mm

  Marks on petals

  there are no noticeable marks on the petals

  Nectar spur

  the flower has no nectar spurs

  Number of carpels

  3

  Number of pistils

  3

  Number of sepals and/or petals

  there are six petals, sepals or tepals in the flower

  Number of styles

  3

  Ovary position

  the ovary is below the point of petal and/or sepal attachment

  Petal and sepal arrangement

  the flower includes only one cycle of petals or sepals

  Petal appearance

  the petals are thin and delicate, and pigmented (colored other than green or brown)

  Petal base

  the petal narrows gradually or does not narrow at the base

  Petal fusion

  • the perianth parts are fused to form a tube, cup, or bell shape
  • the perianth parts are separate

  Petal hairs on inner/upper surface

  there are no hairs on the inner/upper petal surface

  Petal nectaries

  there are nectaries at the petal bases

  Sepal appearance

  the sepals resemble petals in color and texture

  Sepal length

  0.5–2 mm

  Sepal orientation

  • the sepals are pressed against the plant, or jutting stiffly upward
  • the sepals are slightly curved outwards from the plant

  Sepals fused only to sepals

  • the sepals are fused to each other (often along with the petals in monocots), at least near their bases
  • the sepals are separate from one another

  Spathe

  the plant does not have a spathe

  Spathe form

  NA

  Spathe length

  0 mm

  Stamen number

  6

  Stamen position relative to petals

  NA

  Stamen types

  the stamens within a cycle are distinctly of two types

  Stamens fused outwards

  the stamens are fused to the petals or tepals at or near their bases

  Style petal-like

  the style is not broad and flattened like a petal

  Tepals

  the petals and sepals are similar in size and color

• Fruits or seeds

  Berry color

  NA

  Capsule ridges

  there are three ribs or wings on the capsule

  Fruit compartments

  there are three locules in the fruit

  Fruit length

  10–30 mm

  Fruit stalk orientation

  the fruits point upward or spread or curve outward

  Fruit type (general)

  the fruit is dry and splits open when ripe

  Fruit type (specific)

  the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)

  Fruit width

  10–35 mm

  Other markings on berry

  NA

• Glands or sap

  Sap

  the sap is clear and watery

• Growth form

  Lifespan

  the plant lives more than two years

  Root septa

  the roots do not have transverse septa

  Underground organs

  the plant has a rhizome (a horizontal underground stem with roots growing from it)

• Leaves

  Hairs on underside of leaf blade

  • the underside of the leaf is fuzzy or hairy
  • the underside of the leaf is not hairy, or has very few hairs

  Hairs on upper side of leaf blade

  the upper side of the leaf is not hairy, or has very few hairs

  Leaf arrangement

  • alternate: there is one leaf per node along the stem
  • opposite: there are two leaves per node along the stem
  • whorled: there are three or more leaves per node along the stem

  Leaf blade basal lobes

  the leaf blades are lobed at their bases

  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, with rounded lobes) or sagittate (arrow-shaped, with pointed, backward-facing lobes)
  • the base of the leaf blade is rounded
  • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)

  Leaf blade bloom

  the underside of the leaf blade has a noticeable waxy or powdery bloom

  Leaf blade cross-section

  the leaf blade is more or less flat in cross-section

  Leaf blade faces

  both surfaces of the leaf blade are exposed

  Leaf blade form

  Fully-formed (i.e., expanded), +/- green leaf blades are found somewhere on the plant

  Leaf blade length

  30–130 mm

  Leaf blade orientation

  the upper surface of the leaf blade faces the stem of the plant

  Leaf blade shape

  • the leaf blade is cordate (heart-shaped with backward-facing rounded lobes), or sagittate (arrow-shaped with backward-facing pointed lobes)
  • 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 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)
  • the tip of the leaf blade is caudate (has a very long tail-like projection ending in a point)

  Leaf blade veins

  the lateral veins are parallel or slightly arched in the direction of the tip

  Leaf blade width

  20–130 mm

  Leaf stalk length

  30–140 mm

  Leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets

  Leaflet number

  0

  Stipule twining

  NA

  Stipules

  there are no stipules on this plant

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Massachusetts
  • Rhode Island

  Specific habitat

  • edges of wetlands
  • forests
  • river or stream floodplains

• Scent

  Plant odor

  the leaves have no particular smell

• Stem, shoot, branch

  Flowering stem growth form

  the flowering stem trails along the ground or on other vegetation, or floats in the water

  Flowering stem leaves

  there is at least one fully-formed leaf on the flowering stem

  Stem hairs

  • the stem has hairs on it
  • the stem is nearly or completely hairless

Wetland status

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

In New England

From Flora Novae Angliae dichotomous key