 | | Top view of a lone Whitebark Raspberry in a riparian oak woodland within the California North Coast Range |  |
Whitebark Raspberry
Rubus leucodermis
C.Michael Hogan PhD
October 19, 2008
Whitebark Raspberry is a deciduous arching shrub or bramble with a widespread western USA occurrence. Fruits are attractive to many wildlife species, but have also been consumed by humans since prehistoric times.
DISTRIBUTION
R. leucodermis occurs form British Columbia (most typically below 51 degrees northern latitude) southward to California and eastward to Montana, Utah and Nevada. This species is rarely found as far north as southeast Alaska. Elevation occurrence is from 40 to 2400 meters.
MORPHOLOGY
The growth form of Whitebark Raspberry is an arching or erect shrub or bramble attaining a height of 40 to 180 cm.. The smooth main canes are gray to purplish and have a waxy coating. The round stems vary from four to ten mm in diameter and bear a multitude of prickles, which may be straight or recurved; (Abrams) main stems are often curved, especially in the season of principal spring flowering. (Jepson, 1993) The compound leaves are set on petioles of one to five cm in length; leaves are somewhat ovate and have moderate lobing and irregular toothing. The leaves are green above and whitish and hairy below.
Flowers occur in clusters of three to ten in number. The white flower petals are three to five mm in length and are elliptical to oblanceolate in shape. The number of pistils typically exceed 15. The somewhat spherical yellowish-red fruits are characteristic raspberry in appearance, and turn blackish upon full ripening. Two closely related species are: (a) R. melanolasius (Red Raspberry) has red berries that do not turn black when ripe and which have gland-tipped bristles on the upper stems, and (b) R. spectabilis.
ECOLOGY
This plant occurs most frequently in moister areas within its range, preferring ravines and north facing slopes, often on rather steep canyon slopes. It is also found in areas of higher than average precipitation within its range environment. It is tolerant of moderate amounts of shade and can be found in many North Coast Range mixed oak woodland plant associations as well as coastal redwood forests. (Jepson, 1895). Common understory associates in oak woodlands are Western Beaked Hazel, California Huckleberry, Sword Fern and Wild Rose.
The fruit of this species is consumed by many animals as well as humans. Since prehistory the berries have been eaten by Kitasoo, Wuikinuxv, Okanagan, Secwepemc and other Native North American peoples. (Moerman) Fruits are easily separated from the plant when ripe and manifest as juicy, but amply seedy in nature. Seed dispersal is conducted by birds and mammals, who enjoy the ripened berries.
REFERENCES
* LeRoy Abrams (1951) Illustrated Flora of the Pacific States, Stanford University Press, 374 pages ISBN 0804700044
* Jepson Manual (1993) University of California Press, Berkeley, California
* Daniel E. Moerman (1998) Native American Ethnobotany, 927 pages ISBN 0881924539
* Glenn Keator (1978) Pacific Coast Berry Finder, 62 pages, Nature Study Guild, Rochester, N.Y. ISBN 0-912550-02-3
* Willis Linn Jepson (1895) (Keator) Erythea: A Journal of botany, West American and General, University of California, v.3-4
|
|
