Overview
Corallorhiza mertensiana is a leafless, mycoheterotrophic orchid 8-20 inches (20-50 cm) tall that grows without chlorophyll, drawing all of its nutrition from fungi in the forest soil. The whole plant is reddish-pink to purple, consisting of an upright flowering stem with no green leaves. Each stem carries 10-30 small flowers, each about 0.5 inch (1.3 cm) long, with pink to purple sepals and petals and a lip marked with deeper red-purple. Flowers appear from May to August. Below ground, the plant has a branched, coral-like mass of rhizomes, the source of the common name, joined to soil fungi. The fruit is a hanging capsule that releases dust-like seeds. Above-ground stems appear only when flowering and are absent in other years. The plant cannot be transplanted or cultivated because it depends on specific soil fungi tied to forest trees.
Native Range
Native to western North America from Alaska south through the Pacific Northwest to California, and east to the northern Rocky Mountains. Grows in moist, shaded coniferous and mixed forests in deep humus and forest litter, from low elevations to mid mountain slopes.Suggested Uses
Found only in native coniferous forest and woodland preserves, not in cultivated gardens. It is observed in place on shaded forest floors and is not planted, since it cannot survive away from its forest soil fungi. It is of interest in native plant and conservation settings as a forest-floor wildflower.How to Identify
Appearance
Size & Dimensions
Height8" - 1'8"
Width/Spread2" - 4"
Bloom Information
Flowers from May to August, appearing earlier at low elevations and later in the mountains. The flowering stem is the only above-ground part and lasts a few weeks before setting seed and withering. Stems do not appear every year, emerging when the underground fungal connection supports flowering.
Detailed Descriptions
Flower Description
pink to purpleFoliage Description
leafless; stems pink to purpleGrowing Conditions
Sun Requirements
Tolerates up to 2 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight