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White Adder's-mouth (Malaxis monophyllos var. brachypoda)

Life history

Species overview

White Adder's-mouth (Malaxis monophyllos var. brachypoda), a Wisconsin Special Concern plant, is found in neutral or calcareous conifer or black ash swamps. Blooming occurs throughout June; fruiting occurs early July through late August. The optimal identification period for this species is early July through late August.

Synonyms: Malaxis brachypoda, Malaxis monophyllos ssp. brachypoda, Microstylis brachypoda


  • Distinguishing characteristics: Lip narrowly pointed, without lobes.
  • Flower characteristics: Terminal raceme of about 200 small flowers. Very slender inflorescence, tapering to the tip. Flowers upside-down due to twisting of the pedicel, the lip lowermost. Lateral petals oblanceolate, 1 mm, spreading horizontally, Lip greenish-white, deflexed, 2 to 3 mm, broadly cordate, tapering to a long point and with a slightly irregularly toothed margin.
  • Fruit characteristics: Capsule.
  • Leaf characteristics: Solitary, clasping, oval to elliptic, 3 to 6 cm long and usually at least half as wide.


  • Blooming phenology: throughout June
  • Fruiting phenology: early July through late August
  • Optimum time to identify: The optimal identification period for this species is early July through late August


  • Growth form: Forb-erect
  • Vegetative reproduction:
  • Life cycle: Perennial
  • Comments: Associated Species: Thuja occidentalis, Abies balsamea, Fraxinus nigra, Alnus rugosa, Cypripedium reginae, C. parviflorum, Rhamnus alnifolius, Coptis trifolia, Mitella nuda, Betula alleghaniensis.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - state and federal - and the rank (S and G Ranks) for White Adder's-mouth (Malaxis monophyllos var. brachypoda). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where this species has been found to date and is not meant as a range map.

Documented locations of Malaxis monophyllos var. brachypoda in the Natural Heritage Inventory Database as of July 2015.

Summary Information
State StatusSC
Federal Status in Wisconsinnone
State RankS3
Global RankG5T4T5
Tracked by NHIY

Habitats and landscapes

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

General habitat information

  • Habitat description: Found in neutral or calcareous conifer or black ash swamps.
  • Soils: Wet, neutral to calcareous soils.

Natural communities

This table lists the natural communities that are associated with White Adder's-mouth. Scores for natural community associations are: "significant" association (score=3), "moderate association" (score=2) or the species can be present but is only weakly associated with the community (score=1).

Natural communities score
Northern Wet-mesic Forest 3
Northern Hardwood Swamp 3

Ecological landscapes

This table lists the ecological landscape association scores for White Adder's-mouth. The scores (3=High, 2=Moderate, 1=Low, 0=None) also correspond to the map.

Map of the Ecological Landscapes of Wisconsin.

Species guidance

The Endangered Resources Program has developed avoidance measures and management guidelines for plants on the Natural Heritage Working List. These are a work in progress, and we welcome your suggestions and feedback. Sources used in developing this information can be found here.

Avoidance measures

These are specific actions designed to avoid "take" (mortality) of this species.

  • Avoid broadcast spraying of herbicides; use care with spot spraying.
  • Avoid site preparation that heavily disturbs herbaceous ground layer and soil; these include bulldozing and furrowing, as well as grubbing and stump removal.
  • Avoid known individual plant locations and conduct operations elsewhere when they are least likely to cause damage. Ideally, this would involve frozen, snow-covered ground. However, in areas of the state where frozen conditions are unreliable, very dry soils late in the growing season might be the best available alternative. Consult with a biologist, if needed.
  • Avoid locating landings, staging areas, or access routes on or near known populations.

Management guidance

Management guidelines are additional considerations that may help maintain or enhance habitat for this species

  • No guidance has been developed for this species.


White Adder's-mouth Photo.

Photo © Stephen L. Solheim.

White Adder's-mouth Photo.

Photo © Stephen L. Solheim.

White Adder's-mouth Photo.

Photo © Stephen L. Solheim.

Support for Wisconsin's rare plant information has been provided by the Division of Forestry, the Endangered Resources Fund and the Wisconsin Rare Plant Preservation Fund. To donate, visit the Natural Resources Foundation of Wisconsin [exit DNR].

Last revised: Wednesday, May 05, 2021
Southwest Savanna Southern Lake Michigan Coastal Western Coulees and Ridges Southeast Glacial Plains Central Sand Hills Central Lake Michigan Coastal Central Sand Plains Northern Lake Michigan Coastal Northern Lake Michigan Coastal Northeast Sands Western Prairie North Central Forest Northern Highlands Northwest Lowlands Northwest Sands Northwest Lowlands Superior Coastal Plains Forest Transition