Arethusa bulbosa L.

Dragon's Mouth

Facts About

Accepted Synonyms: none

Arethusa bulbosa, commonly known as Dragon's Mouth, is found in eastern and central United States and Canada, from South Carolina to Saskatchewan. It flowers in the summer, producing one bright pink flower with a whitish pink labellum marked with magenta spots and a yellow center. After flowering, it produces a solitary grass-like leaf. While the flowers are showy and fragrant, they offer little or no nectar reward to the pollinator. It is typically found in acidic, boggy conditions, especially favoring a bed of sphagnum mosses. Calopogon tuberosus has similarly colored flowers and grows in the same habitat, but unlike Arethusa, its flowers are non-resupinate (i.e., the labellum is the uppermost petal).

This orchid is considered globally secure, although it is endangered or threatened throughout much of the eastern United States.


The queens of Bombus ternarius and Bombus terricola are attracted to the ultraviolet absorbing anther-like bristles on the lip and crawl toward the base of the lip searching for nectar. As the bumble bee is backing out of the flower, it brushes against the stigma, the anther case is opened and pollinia are then attached to the bee. Self-fertilization is avoided in this process because pollen can be removed only when the insect is leaving the flower and the pollen is transferred to the stigma as it enters the next flower it visits. Pollination is dependent on inexperienced bees that emerge throughout the blooming season because bees quickly learn to avoid these flowers that do not offer a reward.

Ecosystem Type

Bogs, fens, meadows, swamps


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:
  • pink to red
  • white
Nectar spur:
Inflorescence type:
the inflorescence has one flower or a pair of flowers
Labellum characteristics:
  • the labellum is lobed
  • the labellum is simple
Labellum length:
19–35 mm
Sepal length:
20–55 mm
Plant height:
2–40 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 Secure

North America Distribution

Adapted from USDA data