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

Corallorhiza mertensiana Bong.
western coralroot (Pacific coralroot)
Orchidaceae (Orchid family)

Introduction to Vascular Plants

© Kent Brothers  Email the photographer   (Photo ID #10186)

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Distribution of Corallorhiza mertensiana
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Species Information

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Perennial, saprophytic herb from coral-like rhizomes; stems (15) 20-55 cm tall, reddish, smooth.
Bractlike, sheathing, 2 or 3.
Inflorescence a terminal raceme of 3 to 25 short-stalked, erect to spreading flowers, the bracts scalelike; sepals usually pink, narrowly oblanceolate, 7-10 mm long, the lower spreading; lateral petals deep pink to red, veins usually yellow or dark red; lip 6-9 mm long, deep pink to red, usually with 3 dark red veins, base with 2 lateral short teeth, tip irregularly fine-toothed; spur 0.5-2.5 mm long; column 5.5-8 mm long, curved over lip.
Capsules, egg-shaped, drooping, 15-25 mm long.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist to dry forests in the lowland, steppe and montane zones; frequent throughout BC, especially along the coast, south of 55 degrees N, rare northward; N to SE AK and S to WY, ID and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Corallorhiza mertensiana

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 1 726 1420
Slope Gradient (%) 0 30 70
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
35 192 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 3 7
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: CDF(1), CWH(29), ESSF(1), ICH(17), IDF(3), MH(7), MS(1)

Ecological Indicator Information

Shade-tolerant, submontane to subalpine, saprophyte. Western North American. Both species occur on moderately dry to fresh, nitrogen-poor soils within boreal, temperate, and cool mesothermal climates. Sporadic in the mossy understory of coniferous forests on water-shedding and water-receiving sites; commonly associated with Gaultheria shallon, Hylocomium splendens, and Rhytidiadelphus loreus. Oxylophytic species characteristic of Mor humus forms.

SourceIndicator Plants of Coastal British Columbia (Information applies to coastal locations only)


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.

Synonyms and Alternate Names

Corallorhiza maculata subsp. mertensiana (Bong.) Calder & Roy L. Taylor
Corallorrhiza maculata subsp. mertensiana (Bong.) Calder & Taylor [orthographic variant]
Corallorrhiza mertensiana Bong. [orthographic variant]

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References