Epipactis gigantea Douglas ex Hook.

Chatterbox, Stream Orchid

Facts About

Accepted Synonyms: Arthrochilium giganteum, Epipactis americana, Helleborine gigantea

Epipactis gigantea, commonly known as the Stream Orchid or Chatterbox, is distributed from British Columbia south to Arizona into Mexico, and east to Texas. This orchid typically has 4-12 leaves in an alternate arrangement on the stem. It bears an inflorescence of 5-25 green to yellow flowers striped with purple veins on a loose raceme. The lip is distinctly lobed with bright yellow, purple, and orange markings. It blooms throughout the summer and can start flowering as early as March. This orchid favors the shoreline of streams, lakes, seeps, and the sandy soil of marshes and riparian areas.

Epipactis gigantea is considered globally secure, although it may be rare and localized in its wide distribution across North America.


Pollinators for this orchid include syrphid flies such as Dasysyrphus creper, Eupeodes americanus, Eupeodes luniger, Platycheirus immarginatus and most frequently Sphaerophoria philanthus. These flies normally lay their eggs among aphids on which the fly larvae feed. The orchid attracts these flies by producing a fragrance that mimics the smell of honeydew, the sweet liquid excreted by aphids. This fragrance and the bumpy surface on the orchid’s lip, convince the fly it has found a nest of aphids. The fly enters the flower to lay its eggs and any pollen on the fly’s back is scraped off. A new load of pollen is transferred to the fly as it backs out of the flower. Other pollinators include Copestylum satur and Vespula vulgaris.

Ecosystem Type

Bogs, floodplains, marshes, meadows, swamps, woodlands


Leaf arrangement:
Number of leaves on stem:
  • four
  • five
  • six
  • seven or more
Form of the labellum:
the labellum is not pouch-like
Labellum outline:
the labellum is lobed
Main color of labellum:
  • blue to purple
  • crimson
  • orange
  • pink to red
  • yellow
Nectar spur:
Inflorescence type:
the inflorescence is a raceme
Labellum characteristics:
  • the labellum is lobed
  • the labellum is saccate
Labellum length:
14–20 mm
Sepal length:
16–24 mm
Plant height:
30–140 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 Special Concern

North America Distribution

Adapted from USDA data