Shepherdia canadensis (buffaloberry) is a deciduous, dioecious shrub with scurfy, opposite leaves, small yellow or brown flowers and inedible red berries. Found in floodplains and terraces upwards to rocky alpine slopes in Denali, shrubs grow up to 80 cm tall. Leaves are elliptic to ovate in shape and covered with silvery stellate hairs, oppositely arranged and with entire margins. The underside of the leaves have rusty-brown scurfy scales. Branches and stems are brown and also covered in scales. Flowering occurs very early in spring with small clusters of yellowish flowers in the axils of the branches. Flowers open before or during leaf-out soon after snowmelt. The fruit is a reddish drupe containing many ovoid achenes held closely along the stem. Though the red fruits look tasty, one common name 'soapberry' comes from their unappetizing flavor, although bears eat them with abandon. The other shrub in the flora with opposite leaves and red berries is highbush cranberry (Viburnum edule), but that shrub does not have elliptic leaves, or rusty brown scales on stems and leaf undersides.
This species usually flowers right after snow melt in the spring. Berries are mature in late July.
Shepherdia canadensis is dioecious, male and female flowers produced on separate plants. The flowers are pollinated by bee flies (Syrphidae) and dagger flies (Empididae) (Borkent 2004). Pollinated female flowers develop in red fruits. Fruits are eaten by animals, most notably bears, dispersing the seeds in their feces. Seeds need to be cold stratified for germination. Scarification may also be important for germination.
Berries are edible, but bitter and unpleasant, the source of the common name 'soapberry'. Soapberry was traditionally used by Alaska Natives in treating flu and tuberculosis as a tea, skin abrasions, inflammation, infections as a wash or poultice, colds either as tea or raw berries, or simply taken for general ill health (Garibaldi 1999). The bitter berries are easily whipped into a creamlike froth featured in traditional local fare (akutaq, 'Eskimo icecream'). Shepherdia canadensis is an important food source for black and grizzly bears, grouse and snowshoe hares.
Shepherdia canadensis only occurs in North America and ranges from Alaska, into all Canadian provinces then south into the northern and western US states. It occurs in eastern Alaska westward to Kotzebue and the Arctic slope, but is absent or rare in western Alaska, the Alaska Peninsula, the Aleutian Islands, and the southern southeast panhandle region. In Denali, S. canadensis is common and widespread occurring on both sides of the Alaska Range crest.
Within Denali, Shepherdia canadensis grows at elevations 120 m to 1286 m with an average plot elevation of 761 m. It prefers south facing aspects. It grows on low to high angled slopes with an average plot slope of 9 degrees.
Shepherdia canadensis is a nitrogen fixer and early successional species on glacial moraines, gravel bars and nutrient poor soils. It also grows in open rocky woods, lakeshore, riverbanks, old burns, and sub-alpine slopes.