Scientific Name: Epipactis gigantea
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: November 2015
Last COSEWIC Designation: Not at Risk
SARA Status: Schedule 3, Special Concern - (SARA Schedule 1 provisions do not apply)
Image of Giant Helleborine
Giant Helleborine is a perennial, leafy-stemmed orchid up to 1 m tall that spreads from short rhizomes. Flowering stems have 3-15, 2-3 cm wide flowers that are coppery-green to reddish with brownish to purplish veins. Giant Helleborine is one of Canada’s most distinctive showy orchids and has been grown as an ornamental.
Distribution and Population
Giant Helleborine occurs in southern British Columbia (BC) and the western United States as far east as South Dakota and Texas, with at least one collection from central Mexico. In BC, it is known from 23 subpopulations (25 “locations”) in the Columbia and Fraser river drainages, occurring east as far as Fairmont Hot Springs, north as far as Mt. Revelstoke National Park, and west as far as Cultus Lake in the Fraser Valley.
Giant Helleborine grows on wet or moisture-receiving sites including fens, forest seeps, roadside ditches and embankments, stream banks, wet cliffs, lakeshores, and hot spring margins, in direct sunlight or shade. Sites are usually, but not always, calcareous (lime-rich).
Giant Helleborine is a long-lived perennial that reproduces both sexually (from seeds) and vegetatively (from rhizomes). Aboveground stems (ramets) emerge in the spring and die back in the fall; the flowers bloom between June and August in BC. Each fruit capsule contains thousands of tiny wind- or water-dispersed seeds. Although seedlings have been observed in the field, the most common reproductive strategy appears to be through vegetative spread. The species’ clonal nature allows it to form densely packed aggregations containing hundreds or sometimes thousands of ramets. Only a fraction of mature ramets produce flowers in any given year; many (typically >70%) produce only leafy stems. The average age of Giant Helleborine plants in Canada is estimated to be 10+ years. The species appears to be tolerant of interspecific competition and is found in both early- and late-successional habitats. However, availability of suitable microsites for seedling recruitment and establishment may be limiting. Although occasional long-distance dispersal events evidently do occur, rescue from populations outside Canada is highly unlikely.
The majority of Giant Helleborine subpopulations in Canada are currently considered secure. Where they have been identified, the most serious plausible threats are from (a) droughts that lower the water table or otherwise alter the hydrological regime, (b) habitat loss associated with land development, and (c) recreation-related disturbances such as trampling.
Other Protection or Status
The Giant Helleborine is protected from international trade under the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
1 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
COSEWIC Status Reports
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