E-Flora BC: Electronic Atlas of the Flora of British Columbia

Epipactis gigantea Douglas ex Hook.
giant helleborine (stream orchid)
Orchidaceae (Orchid family)

Introduction to Vascular Plants

© Ian Gardiner  Email the photographer   (Photo ID #16059)

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Distribution of Epipactis gigantea
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Giant Helleborine is a large, perennial, rhizomatous orchid species that in North America is found in the western half of the continental United States and in one Canadian province (British Columbia) (USDA 2011). In British Columbia, it is found in the southern part of the province, in "moist streambanks, fens, marshes and swamps, and around hot springs in the lowland and montane zones" (Douglas et al. 2001).

Lomer (2011) describes this species in the Fraser Valley: "This robust orchid of wet, often calcareous sites, was known in the Fraser Valley from Cultus Lake where it was collected more than 70 years ago (UBC: H.H. Rose s.n.). It was rediscovered there in 2004 (UBC: Lomer 5404). It is quite frequent along the northern lakeshore for 100 meters. It is not yet threatened on this undeveloped side of Cultus Lake, though the near-constant summertime wave action caused by boaters is battering the shoreline plants. In 2009 a large population of E. gigantea was discovered by Monica Pearson in a wetland east of Agassiz. As well, a few small patches exist on the Fraser River islands southwest of Agassiz. Surprisingly, these plants are not in wet sites in summer, but are moistened or even inundated during high runoff." [Originally reprinted from Botanical Electronic News # 435, with permission.]

Species Information

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Perennial herb from short rhizomes and clustered, thickened roots; stems 30-100 cm tall, leafy, sparsely hairy.
Stem leaves lanceolate to widely elliptic, 5-15 cm long, ribbed, gradually reduced upward and downward.
Inflorescence terminal, somewhat 1-sided, of several showy flowers, the bracts leaflike; sepals green to reddish, purple-veined, lanceolate to egg-shaped, 12-20 mm long, the lower sepals spreading to descending; lateral petals similar to sepals, 13-15 mm long, ascending or curved forward; lip 14-20 mm long, saclike at base, 3-lobed, lower half deeply concave, greenish to yellowish, red-purple-veined, upper half grooved, yellow, reddish-tinged or -veined below; column 5-9 mm long, curved over lip.
Capsules, ellipsoid, spreading to drooping, 2-3 cm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist streambanks, fens, marshes and swamps, and around hot springs in the lowland and montane zones; rare in S BC; S to TX, NM, AZ and CA.

Source: The Illustrated Flora of British Columbia


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Taxonomic and Nomenclatural Links

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General References