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- Isotria medeoloides
Isotria medeoloides — small whorled pogonia
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Facts
Small whorled pogonia is globally rare, with most of the world's population occuring in Maine and New Hampshire, where it typically grows in young, open-canopy forests, and disappearing from more mature forests. Plant size and reproduction is positively correlated with light levels, and a small test of canopy thinning appears to confirm this, suggesting a potential conservation tool.
Habitat
Anthropogenic (man-made or disturbed habitats), forest edges, forests
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.
Found this plant? Take a photo and post a sighting.
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
- 11–16 mm
- Sepal length
- 12–25 mm
-
Flowers
- Flower petal color
- green
- Flower symmetry
- there is only one way to evenly divide the flower (the flower is bilaterally symmetrical)
- Flowering date
-
- July
- June
- May
- Flowers per inflorescence
- 1–3
- 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
- 10–15 mm
- Length of narrowed base of lower petal
- 0 mm
- Length of peduncle
- 10–15 mm
- Lobes at base of lower petal
- 0 mm
- Lower petal characteristics
- the labellum is lobed
- Lower petal length
- 11–16 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
- Self-pollinating flowers
- there are no cleistogamous flowers on this plant
- Sepal length
- 12–25 mm
- Sepals fused only to sepals
- the sepals are separate from one another
- Shape of viscidium
- NA
- Spots on lower petal
- no
- Spur opening membrane
- NA
- Spur opening shape
- NA
-
Fruits or seeds
- Fruit length
- 12–28 mm
- Fruit width
- 2–10 mm
- Length of peduncle when in fruit
- 5–20 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
- 17–85 mm
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both 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 acute (sharply pointed)
- Leaf blade width
- 8–40 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
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
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
- extremely rare (S-rank: S1), endangered (code: E)
- Maine
- rare (S-rank: S2), endangered (code: E)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- rare (S-rank: S2), threatened (code: T)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
- Vermont
- extirpated (S-rank: SX), endangered (code: E)
From Flora Novae Angliae dichotomous key
1. Isotria medeoloides (Pursh) Raf. NC
small whorled pogonia. Arethusa medeoloides Pursh; Pogonia affinis Austin ex Gray • CT, MA, ME, NH, RI, VT. Deciduous or evergreen-deciduous, often acidic, forests, usually relatively young forests with an open understory, frequently associated with mild topography and growing in the vicinity of small streams. Vegetative plants of Isotria medeoloides superficially resemble Medeola virginiana. The former has glabrous, hollow stems that arise from short rhizomes, while the latter has pubescent, solid stems that arise from a white tuber.
Native to North America?
Yes