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- Malaxis monophyllos
Malaxis monophyllos — white adder's-mouth
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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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Facts
White adder's-mouth has a circumboreal distribution, but is rare in New England. It is usually found in fens and swamps with northern white-cedar (Thuja occidentalis).
Habitat
Fens, ridges or ledges, swamps
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
- Number of leaves on stem
-
- one
- 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 is a raceme (a long unbranched stem with stalked flowers growing along it)
- Lower petal characteristics
- the labellum is lobed
- Lower petal length
- 1.3–2.2 mm
- Sepal length
- 1.5–2.5 mm
-
Flowers
- Flower bract length
- 1.5–2 mm
- Flower petal color
-
- green
- white
- yellow
- 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
- 5–80
- Form of lower petal
- the labellum does not have a pouch-like shape
- Hairs on flower stalk
- the flower stalk has no hairs on it
- Hairs on inflorescence axis
- the main stem of the inflorescence is hairless
- Inflorescence length
- 10–120 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
- Length of flower stalk
- 2–4.5 mm
- Length of narrowed base of lower petal
- 0 mm
- Length of peduncle
- 100–250 mm
- Lower petal characteristics
- the labellum is lobed
- Lower petal length
- 1.3–2.2 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
- the lateral petals slant outward
- Self-pollinating flowers
- there are no cleistogamous flowers on this plant
- Sepal length
- 1.5–2.5 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
- 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 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
- 15–95 mm
- Leaf blade length to width ratio
- 1.5–1.9
- Leaf blade shape
-
- the leaf blade is elliptic (widest near the middle and tapering at both ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade tip
- the tip of the leaf blade is acute (sharply pointed)
- Leaf blade width
- 10–50 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
-
- one
- two
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- fens
- ridges or ledges
- swamps
Wetland status
Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)
New England distribution and conservation status
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.
ssp. brachypoda
- Maine
- extremely rare (S-rank: S1), endangered (code: E)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- historical (S-rank: SH), endangered (code: E)
- Vermont
- rare to uncommon (S-rank: S2S3), threatened (code: T)
Native to North America?
Yes
Synonyms
- Malaxis brachypoda (Gray) Fern.
- Malaxis monophyllos (L.) Sw. var. brachypoda (Gray) F. Morris & Eames
Family
Genus
Notes on subspecies and varieties in New England
Our subspecies is Malaxis monophyllos (L.) Sw. ssp. brachypoda.
From the dichotomous key of Flora Novae Angliae
2. Malaxis monophyllos (L.) Sw. ssp. brachypoda (Gray) A. & D. Löve NC
white adder’s-mouth. Malaxis brachypoda (Gray) Fern.; M. monophyllos (L.) Sw. var. brachypoda (Gray) F. Morris & Eames • CT, MA, ME, NH, VT; widespread (at least historically) in the northern states, but missing from southern and eastern-central New England. Fens and evergreen swamps, usually in the shade of Thuja occidentalis, rarely on open ledges.