Malaxis monophyllos (L.) Sw.

White Adder's Mouth, White Adder's Tongue

Facts About

Accepted Synonyms: Malaxis brachypoda, Malaxis diphyllos

Malaxis monophyllos, or White Adder's Mouth, has a wide distribution across northern Canada and the United States, from southern Alaska to Newfoundland and around the Great Lakes, with disjunct populations in California and Colorado. It bears a single leaf and a slender inflorescence of minute, white or greenish yellow flowers which can either have a resupinate or non-resupinate labellum, depending on the variety. This orchid usually grows in wet areas such as bogs or swamps where its small size and green coloration make it virtually indistinguishable from the surrounding vegetation.

Malaxis monophyllos is globally considered secure, although it is considered rare in several states throughout its range.


This orchid is pollinated by fungus gnats.

Notes on Subspecies and Varieties

Two varieties of Malaxis monophyllos have been recognized and are easily distinguished by the position of the lip.
Malaxis monophyllos var. monophyllos, the typical variety, is found throughout Europe and Asia but is restricted in North America to Alaska and British Columbia. This variety has the lip in the uppermost position in the flower.
Malaxis monophyllos var. brachypoda is found throughout North America and has resupinate flowers, with the lip in the lowermost position in the flower.

Ecosystem Type

Bogs, cliffs balds or ledges, fens, forests, grassland, meadows, ridges or ledges, stream bank, swamps


Leaf arrangement:
  • alternate
  • stem
Number of leaves on stem:
  • one
  • two
  • three
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is lobed
Main color of labellum:
  • green to brown
  • white
  • yellow
Nectar spur:
Inflorescence type:
the inflorescence is a raceme
Labellum characteristics:
the labellum is lobed
Labellum length:
1.3–2.2 mm
Sepal length:
1.5–2.5 mm
Plant height:
3–30 cm
Show All Characteristics

Native to North America


North American Conservation Status & Distribution

Conservation Status

Select a location to view conservation status:

Conservation and Wetland Status
Global Rank Secure
US Status N/A
Canadian Status Secure

North America Distribution

Adapted from USDA data