Isotria verticillata (Muhl. ex Willd.) Raf.

large whorled pogonia

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Large whorled pogonia may form extensive clones with hundreds of stems. It is pollinated by several groups of native bees, and although it has apparent nectar guides, it provides no nectar. The pollen is deposited on the bees' thorax, but is not confined in pollinia, so that several consecutive bees can pick up pollen from the same flower.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, forests, woodlands

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf arrangement
whorled: there are three or more leaves per node along the stem
Number of leaves on stem
  • five
  • four
  • six or more
  • three
  • two
Form of lower petal
the labellum does not have a pouch-like shape
Lower petal outline
the labellum is lobed but not fringed
Main color of lower petal
  • green to brown
  • white
  • yellow
Nectar spur
there are no nectar spurs on the flower
Inflorescence type
the inflorescence has only one flower or a pair of flowers on it
Lower petal characteristics
the labellum is lobed
Lower petal length
15–25 mm
Sepal length
34–67 mm
Show All Characteristics
  • Flowers
    Flower bract length
    0 mm
    Flower petal color
    • green
    • yellow
    Flower symmetry
    there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
    Flowering date
    • June
    • May
    Flowers per inflorescence
    1–2
    Form of lower petal
    the labellum does not have a pouch-like shape
    Hairs on inflorescence axis
    NA
    Inflorescence type
    the inflorescence has only one flower or a pair of flowers on it
    Labellum position
    the labellum is in the lower position on the flower
    Length of flower stalk
    20–55 mm
    Length of narrowed base of lower petal
    0 mm
    Length of peduncle
    20–55 mm
    Lobes at base of lower petal
    0 mm
    Lower petal characteristics
    the labellum is lobed
    Lower petal length
    15–25 mm
    Lower petal outline
    the labellum is lobed but not fringed
    Lower petal strongly red-veined
    no
    Main color of lower petal
    • green to brown
    • white
    • yellow
    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
    Pollen sacs
    the pollinia remain intact and do not fragment into smaller parts
    Self-pollinating flowers
    there are no cleistogamous flowers on this plant
    Sepal length
    34–67 mm
    Sepals fused only to sepals
    the sepals are separate from one another
    Spots on lower petal
    no
    Spur opening membrane
    NA
    Spur opening shape
    NA
  • Fruits or seeds
    Fruit length
    20–42 mm
    Fruit width
    5–10 mm
    Length of peduncle when in fruit
    20–55 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
    NA
    Features of leaves
    the leaf does not have any of the mentioned special features
    Leaf arrangement
    whorled: there are three or more leaves per node along the stem
    Leaf blade edges
    the edges of the leaf blade have no teeth
    Leaf blade length
    25–100 mm
    Leaf blade length to width ratio
    1.9–2.5
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the leaf blade is oblong (rectangular but with rounded ends)
    • 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 acuminate (tapers to a long, thin point)
    • the tip of the leaf blade is obtuse (bluntly pointed)
    Leaf blade width
    10–53 mm
    Leaves during flowering
    there are leaves on the plant when it is flowering
    Number of bracts on stem
    0
    Number of leaves on stem
    • five
    • four
    • six or more
    • three
    • two
  • Place
    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of forests
    • forests
    • man-made or disturbed habitats
    • woodlands

Wetland Status

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

New England Distribution and Conservation Status

Distribution

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

Conservation Status

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

Connecticut
uncommon (S-rank: S3)
Maine
extirpated (S-rank: SX), potentially extirpated (code: PE)
Massachusetts
uncommon to fairly widespread (S-rank: S3S4)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)
Rhode Island
rare (S-rank: S2), concern (code: C)
Vermont
rare (S-rank: S2), threatened (code: T)

Native to North America?

Yes

Sometimes Confused With

Isotria medeoloides:
sepals 12–25 mm long, usually green-yellow throughout, and labellum 10–15 mm long (vs. I. verticillata, with sepals 34–67 mm long, usually green-yellow in the basal portion and red-purple in the apical portion, and labellum 15–25 mm long).

Synonyms

  • Arethusa verticillata Muhl. ex Willd.
  • Pogonia verticillata (Muhl. ex Willd.) Nutt.

Family

Orchidaceae

Genus

Isotria

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Information from Dichotomous Key of Flora Novae Angliae

2.  Isotria verticillata (Muhl. ex Willd.) Raf. N

large whorled pogonia. Arethusa verticillata Muhl. ex Willd.; Pogonia verticillata (Muhl. ex Willd.) Nutt. • CT, MA, ME, NH, RI, VT. Mesic to dry-mesic, often acidic, forests and woodlands.