Hammarbya paludosa (L.) Kuntze

Bog Adder's Mouth, Bog Malaxis, Marsh Malaxis

Facts About

Accepted Synonyms: Malaxis paludosa, Epipactis paludosa, Malaxis palustris, Ophrys paludosa, Ophrys palustris

Hammarbya paludosa, commonly known as Bog Adder's Mouth, is circumboreal, occurring in Alaska, Minnesota, Canada, Europe, and Asia. This small, inconspicuous plant grows in conifer swamps, wet coniferous forests, tundra, sphagnum bogs, mossy fens, and muskegs. The stem is swollen at the base into a round pseudobulb. Foliar embryos are produced at the tips of the two to five basal leaves. The long, narrow raceme has tiny, yellow greenish flowers. The sepals are bent backward, as are petals. The labellum is trowel-shaped, has dark green veins, and is positioned uppermost in the flower.

Hammarbya paludosa is considered globally secure although it does face threats in North America.


This orchid is pollinated by Phronia digitata, a fungus gnat. After visiting the flower the observed fungus gnat had pollinia attached behind its mouthparts on the thorax. The fungus gnat may use it’s proboscis to go over the column to access nectar and acquires pollinia on its anterior ventral thorax. Pollen is then transferred to the stigma of the next flower visited.

Ecosystem Type

Bogs, fens, forests, swamps, tundra, woodlands


Leaf arrangement:
Number of leaves on stem:
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is simple
Main color of labellum:
  • green to brown
  • yellow
Nectar spur:
Inflorescence type:
the inflorescence is a raceme
Labellum characteristics:
the labellum is simple
Labellum length:
1.2–1.8 mm
Sepal length:
2–3 mm
Plant height:
3–23 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 Apparently Secure
US Status N/A
Canadian Status May Be At Risk

North America Distribution

Adapted from USDA data