Platanthera macrophylla — large-leaved bog-orchid
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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
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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- Number of leaves on stem
- absent
- 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
-
- green to brown
- white
- Nectar spur
- the flower has at least one nectar spur on it
- Inflorescence type
- the inflorescence is a raceme (a long unbranched stem with stalked flowers growing along it)
- Lower petal characteristics
- the labellum is simple in form
- Lower petal length
- 10–23 mm
-
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)
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.
- Massachusetts
- rare (uncertain) (S-rank: S2?)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
- Vermont
- extremely rare (S-rank: S1)
From Flora Novae Angliae dichotomous key
13. Platanthera macrophylla (Goldie) Lindl. N
large-leaved bog-orchid. Habenaria macrophylla Goldie; H. orbiculata Pursh var. macrophylla (Goldie) Boivin; Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer • CT, MA, ME, NH, RI, VT. Mesic to wet-mesic forests.
Native to North America?
Yes
Sometimes confused with
- Platanthera hookeri:
- scape with 0 very rarely 1 bract-like leaves, ovary sessile, flowers green to green-yellow, and labellum upcurved (vs. P. macrophylla, with the scape with 1–6 bract-like leaves, ovary on a stipe 5–10 mm long, flowers white to green-white, and labellum downward oriented).
- Platanthera orbiculata:
- spur mostly 10-26 mm long (vs. P. macrophylla, with a spur mostly 28-46 mm long).
Synonyms
- Habenaria macrophylla Goldie
- Habenaria orbiculata Pursh var. macrophylla (Goldie) Boivin
- Platanthera orbiculata var. macrophylla (Goldie) Luer