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

Perideridia gairdneri (Hook. & Arn.) Mathias
Gairdner's yampah

Introduction to Vascular Plants

© Liz Watkinson  Email the photographer   (Photo ID #21541)

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Distribution of Perideridia gairdneri
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Species Information

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Slender perennial herb from tuberous-thickened and often clustered edible root, often fascicled, glabrous; stems solitary, 0.4-1.2 m tall.
Several, well distributed along stem, divided 1-3 times, elongate; basal leaf sheaths not much inflated; ultimate segments long and narrow.
Inflorescence of compound umbels; flowers terminal and lateral; spokes up to 6 cm long at maturity; flowers white or pink; involucel bractlets bristly or obsolete.
Roundish, 2-3 mm long and wide, slightly flattened, glabrous, prominent ribs.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA

Habitat / Range

Moist to dry meadows and woodlands in the lowland and montane zones; infrequent in SE and SW BC (known from SE Vancouver Island and the Gulf Islands), also rare in SC BC; E to SK and S to SD, CO, NM and CA.

Source: The Illustrated Flora of British Columbia

Ecological Indicator Information

A very shade-intolerant, submontane to montane. North American forb distributed equally in the Pacific, Cordilleran, and Atlantic regions. Occurs in maritime to submaritime summer-dry cool mesothermal climates on moderately dry to fresh, nitrogen-medium soils; its occurrence increases with increasing temperature and decreases with increasing precipitation. Scattered in forest openings and non-forested communities on water-shedding sites. Characteristic of moisture-deficient sites.

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 cool mesothermal.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References