Malaxis monophyllos (White Adder's-mouth)

Plant Info
Also known as:
Family:Orchidaceae (Orchid)
Life cycle:perennial
  • State Special Concern
Habitat:part shade, shade; sphagnum hummocks in conifer swamps, peat soil in hardwood swamps
Bloom season:June - July
Plant height:4 to 9 inches
Wetland Indicator Status:GP: FACW MW: FACW NCNE: FACW
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

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Detailed Information

Flower: Flower shape: irregular Cluster type: raceme

[photo of flowers] A slender spike-like raceme up to 4½ inches (11.5 cm) at the tip of the stem with 12 to 35 stalked, green to greenish white flowers. The lower lip is broad at the base and abruptly narrowed in the middle, producing an elongated, narrowly triangular tip; lateral petals are shorter, more lance-linear and curve back. The 3 sepals are each less than 1/8 inch (1 to 2.5 mm) long, egg-shaped tapering to a pointed tip, the upper sepal erect, the lateral sepals drooping.

Leaves and stems: Leaf type: simple

[photo of leaf] A single leaf, 1 to 3¾ inches (9.5 cm) long, up to 2 inches (5 cm) wide, elliptical to egg-shaped, sheathes the stem near the base, rarely at the base. The stem is smooth with another sheath at the base.

Fruit: Fruit type: capsule/pod

[photo of developing fruit] Fruit is an elliptic, ascending capsule up to 5 mm (~1/6 inch) long.


White Adder's-mouth is an inconspicuous occupant of cedar-spruce bogs and tamarack swamps in northern Minnesota. According to the DNR, while found at numerous locations, population sizes at any one spot are small, often fewer than 10 plants. It was listed as a State Special Concern species in 1996 due to its low numbers and the fragile nature of its habitat. There are 2 recognized varieties: var. brachypoda is the North American species and var. monophyllos its Eurasian counterpart, though these are split to separate species in some references, making Malaxis brachypoda present in Minnesota. The single leaf may be mistaken for the related Green Adder's-mouth (Malaxis unifolia), which has its leaf positioned about mid-stem and has a distinctly cylindrical flower cluster.

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More photos

Photos by Peter M. Dziuk taken in Hubbard County. Photos by John Thayer taken in Cass County.


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