Isotria verticillata — large whorled pogonia
![Inflorescences: Isotria verticillata. ~ By Dorothy Long. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Orchidaceae/isotria-verticillata-in-dlong.jpg)
![Flowers: Isotria verticillata. ~ By Dorothy Long. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Orchidaceae/isotria-verticillata-fl-dlong.jpg)
![Flowers: Isotria verticillata. ~ By Frank Bramley. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Orchidaceae/isotria-verticillata-fl-fbramley-a.jpg)
![Flowers: Isotria verticillata. ~ By Gordon Morrison. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Orchidaceae/isotria-verticillata-fl-gmorrison.jpg)
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Facts
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
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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enlargeCharacteristics
- 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
-
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)
In New England
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)
From Flora Novae Angliae dichotomous key
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.
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.