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• Platanthera
• Platanthera obtusata

Platanthera obtusata — blunt-leaved bog-orchid

Facts

Blunt-leaved bog-orchid has a circumboreal and alpine distribution, and is found in New England from Massachusetts north. This orchid has the distinction of being the only North American plant that is confirmed to be pollinated by mosquitoes, although there may be others.

Habitat

Fens, forests, meadows and fields, swamps

Characteristics

• Flowers

  Flower petal color

  • green
  • white
  • yellow

  Flower symmetry

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

  Flowering date

  • August
  • July
  • June

  Flowers per inflorescence

  2–20

  Form of lower petal

  the labellum does not have a pouch-like shape

  Hairs on inflorescence axis

  the main stem of the inflorescence is hairless

  Inflorescence length

  25–170 mm

  Inflorescence type

  the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)

  Labellum position

  the labellum is in the lower position on the flower

  Length of narrowed base of lower petal

  0 mm

  Length of peduncle

  100–300 mm

  Lobes at base of lower petal

  0 mm

  Lower petal characteristics

  • the labellum has spurs on it
  • the labellum is simple in form

  Lower petal length

  2.5–10 mm

  Lower petal outline

  the labellum is simple in form

  Lower petal strongly red-veined

  no

  Main color of lower petal

  • green to brown
  • white
  • yellow

  Nectar spur

  the flower has at least one nectar spur on it

  Nectar spur length

  3–10 mm

  Number of stamens

  1

  Orientation of side petals

  the lateral petals are angled steeply upwards

  Pollen sacs

  the pollinia remain intact and do not fragment into smaller parts

  Self-pollinating flowers

  there are no cleistogamous flowers on this plant

  Sepals fused only to sepals

  the sepals are separate from one another

  Shape of viscidium

  the viscidium is roughly circular

  Spots on lower petal

  no

  Spur opening membrane

  there is no membrane over the spur opening

• Fruits or seeds

  Fruit length

  Up to 10 mm

  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

  • there are only slender roots on the plant
  • this plant has a rhizome (a horizontal underground stem with roots growing from it)

• 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

  basal: the leaves are growing only at the base of the plant

  Leaf blade edges

  the edges of the leaf blade have no teeth

  Leaf blade length

  35–150 mm

  Leaf blade length to width ratio

  3–4.4

  Leaf blade shape

  • the leaf blade is elliptic (widest near the middle and tapering at both ends)
  • the leaf blade is linear (very narrow with more or less parallel sides)
  • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
  • the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)

  Leaf blade tip

  the tip of the leaf blade is obtuse (bluntly pointed)

  Leaf blade width

  8–50 mm

  Leaves during flowering

  there are leaves on the plant when it is flowering

  Number of bracts on stem

  0–1

  Number of leaves on stem

  • absent
  • one

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont

  Specific habitat

  • fens
  • forests
  • meadows or fields
  • swamps

Wetland status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae