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• Platanthera macrophylla

Platanthera macrophylla — large-leaved bog-orchid

Facts

Large-leaved bog-orchid is true to its name, with very large basal leaves resting more or less flat on the ground. A study of bog-orchids (Platanthera) showed that species with longer nectar spurs (which makes nectar available only to insects with longer mouth parts) also tend to have more restricted geographical distributions. Large-leaved bog-orchid has unusually large nectar spurs, is pollinated by large moths, and is restricted to northeastern North America.

Habitat

Forests, swamps

Characteristics

• Flowers

  Flower petal color

  • green
  • white

  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

  9–33

  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

  80–350 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

  Lobes at base of lower petal

  0 mm

  Lower petal characteristics

  the labellum is simple in form

  Lower petal length

  10–23 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

  Nectar spur

  the flower has at least one nectar spur on it

  Nectar spur length

  28–46 mm

  Number of stamens

  1

  Orientation of side petals

  the lateral petals slant outward

  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

  18–25 mm

  Fruit width

  4–6 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

  • 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

  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

  70–240 mm

  Leaf blade length to width ratio

  1.3–1.4

  Leaf blade shape

  • the leaf blade is elliptic (widest near the middle and tapering at both ends)
  • the leaf blade is orbicular (roughly circular, as wide as long)
  • the leaf is a shape other than those described

  Leaf blade tip

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

  Leaf blade width

  50–190 mm

  Leaves during flowering

  there are leaves on the plant when it is flowering

  Number of bracts on stem

  0–6

  Number of leaves on stem

  absent

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • forests
  • swamps

Wetland status

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

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae