Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

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

Platanthera dilatata — white northern bog-orchid

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Northern bog-orchid is known to be pollinated by noctuid moths, although this observation was not made in New England. The Thompson Indians used this plant in sweatbaths for relief of rheumatic and other joint and muscle pains. They also used it as a wash for good luck.

Habitat

Alpine or subalpine zones, anthropogenic (man-made or disturbed habitats), bogs, cliffs, balds, or ledges, fens (calcium-rich wetlands), ridges or ledges, shores of rivers or lakes, swamps, wetland margins (edges of wetlands)

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Vermont
Leaf arrangement
alternate: there is one leaf per node along the stem
Form of lower petal
the labellum does not have a pouch-like shape
Lower petal outline
the labellum is simple in form
Main color of lower petal
white
Nectar spur
the flower has at least one nectar spur on it
Inflorescence type
the inflorescence is a spike (a long unbranched stem with flowers along it that lack stalks)
Lower petal characteristics
  • the labellum has spurs on it
  • the labellum is simple in form
Lower petal length
4–11 mm
Show all characteristics
  • Flowers

    Flower bract length
    Up to 40 mm
    Flower petal color
    white
    Flower symmetry
    there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
    Flowering date
    • August
    • July
    • June
    • September
    Flowers per inflorescence
    9–65
    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
    100–300 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
    Length of narrowed base of lower petal
    0 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
    4–11 mm
    Lower petal outline
    the labellum is simple in form
    Lower petal strongly red-veined
    no
    Main color of lower petal
    white
    Nectar spur
    the flower has at least one nectar spur on it
    Nectar spur length
    4–12 mm
    Number of stamens
    1
    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 another shape than the choices given
    • the viscidium is long and narrow
    Spots on lower petal
    no
    Spur opening membrane
    there is no membrane over the spur opening
  • 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 longer than the associated flower
    • the bract is shorter than the associated flower
    Features of leaves
    the leaf does not have any of the mentioned special features
    Leaf arrangement
    alternate: there is one leaf per node along the stem
    Leaf blade edges
    the edges of the leaf blade have no teeth
    Leaf blade length
    35–320 mm
    Leaf blade length to width ratio
    4.6–11.7
    Leaf blade shape
    • the leaf blade is lanceolate (lance-shaped; widest below 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 oblong (rectangular but with rounded 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
    3–70 mm
    Leaves during flowering
    there are leaves on the plant when it is flowering
  • Place

    Habitat
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • bogs
    • cliffs, balds, or ledges
    • edges of wetlands
    • fens (calcium-rich wetlands)
    • man-made or disturbed habitats
    • ridges or ledges
    • shores of rivers or lakes
    • swamps

Wetland status

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

In New England

Distribution

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

Conservation status

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

Connecticut
historical (S-rank: SH), special concern, extirpated (code: SC*)
Massachusetts
rare (S-rank: S2), threatened (code: T)

var. dilatata

Massachusetts
unranked (S-rank: SNR)

Subspecies and varieties

Our variety is Platanthera dilatata (Pursh) Lindl. ex Beck var. dilatata.

From Flora Novae Angliae dichotomous key

6.  Platanthera dilatata (Pursh) Lindl. ex Beck var. dilatata N

white northern bog-orchid. Habenaria dilatata (Pursh) Hook.; Limnorchis dilatata (Pursh) Rydb. • MA, ME, NH, VT. Bogs, fens, wet openings in boreal and subalpine forests, river shores, bases of wet, high-elevation cliffs, ditches.

Native to North America?

Yes

Synonyms

  • Habenaria dilatata (Pursh) Hook.
  • Limnorchis dilatata (Pursh) Rydb.

Family

Orchidaceae

Genus

Platanthera