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• Spiranthes tuberosa

Spiranthes tuberosa — little ladies'-tresses

Facts

Little ladies'-tresses is primarily a species of the southern and southeastern states, but it enters New England (Connecticut, Massachusetts and Rhode Island) at the northern limit of its distribution. It is relatively common in much of its range, but not so in New England. It is distinguished from close relatives by its pure white flowers and single tuberous root (occasionally the previous year's tuber persists).

Habitat

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

Characteristics

• Flowers

  Flower petal color

  white

  Flower symmetry

  there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)

  Flowering date

  • August
  • September

  Flowers per inflorescence

  8–30

  Form of lower petal

  the labellum does not have a pouch-like shape

  Hairs on flower stalk

  NA

  Hairs on inflorescence axis

  the main stem of the inflorescence is hairless

  Inflorescence length

  15–80 mm

  Inflorescence type

  the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)

  Labellum position

  the labellum is in the lower position on the flower

  Length of flower stalk

  0 mm

  Lobes at base of lower petal

  0 mm

  Lower petal characteristics

  the labellum is simple in form

  Lower petal outline

  the labellum is simple in form

  Lower petal strongly red-veined

  no

  Main color of lower petal

  white

  Nectar spur

  there are no nectar spurs on the flower

  Nectar spur length

  0 mm

  Number of stamens

  1

  Orientation of side petals

  • the lateral petals are angled steeply upwards
  • the lateral petals slant somewhat downward

  Self-pollinating flowers

  there are no cleistogamous flowers on this plant

  Sepal length

  3–5 mm

  Sepals fused only to sepals

  the sepals are separate from one another

  Shape of viscidium

  • the viscidium is lance-shaped (wider near one end, pointed at the ends)
  • the viscidium is long and narrow

  Spots on lower petal

  no

  Spur opening membrane

  NA

  Spur opening shape

  NA

• Fruits or seeds

  Seed capsule orientation

  the capsule points upwards or is angled outwards

• Growth form

  Plant green or not

  the plant is chlorophyllous (it has green parts)

  Roots

  the rhizomes do not resemble coral

  Underground organs

  • the plant has one or more swollen storage organs underground, such as bulbs, tubers or corms
  • there are only slender roots on the plant

• Leaves

  Bract relative length

  the bract is shorter than the associated flower

  Features of leaves

  the leaf does not have any of the mentioned special features

  Leaf arrangement

  the leaves are growing only at the base of the plant (basal)

  Leaf blade edges

  the edges of the leaf blade have no teeth

  Leaf blade length

  20–60 mm

  Leaf blade length to width ratio

  2–3

  Leaf blade shape

  • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
  • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)

  Leaf blade tip

  • the tip of the leaf blade is acute (sharply pointed)
  • the tip of the leaf blade is obtuse (bluntly pointed)

  Leaf blade width

  10–20 mm

  Leaves during flowering

  • there are leaves on the plant when it is flowering
  • there are no leaves on the plant when it is flowering

  Number of bracts on stem

  4–6

  Number of leaves on stem

  absent

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Massachusetts
  • Rhode Island

  Specific habitat

  • grasslands
  • man-made or disturbed habitats
  • meadows or fields
  • woodlands

Wetland status

Occurs only in non-wetlands. (Wetland indicator code: UPL)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae