Arctostaphylos uva ursi

Distribution

The distribution of Arctostaphylos uva-ursi is circumpolar, and it is widespread in northern latitudes, but confined to high altitudes further south:

In some areas, the plant is endangered or has been extirpated from its native range. In other areas, such as the Cascade Range, it is abundant.

Description

Arctostaphylos uva-ursi is a small procumbent woody groundcover shrub 5–30 cm high. The leaves are evergreen, remaining green for 1–3 years before falling. The fruit is a red berry.

The leaves are shiny, small, and feel thick and stiff. They are alternately arranged on the stems. Undersides of leaves are lighter green than on the tops. New stems can be red if the plant is in full sun, but are green in shadier areas. Older stems are brown. In spring, they have white or pink flowers.

Pure stands of Arctostaphylos uva-ursi can be extremely dense, with heights rarely taller than 6 inches. Erect branching twigs emerge from long flexible prostrate stems, which are produced by single roots. The trailing stems will layer, sending out small roots periodically. The finely textured velvety branches are initially white to pale green, becoming smooth and red-brown with maturity. The small solitary three-scaled buds are dark brown.

The simple leaves of this broadleaf evergreen are alternately arranged on branches. Each leaf is held by a twisted leaf stalk, vertically. The leathery dark green leaves are an inch long and have rounded tips tapering back to the base. In fall, the leaves begin changing from a dark green to a reddish-green to purple.

Terminal clusters of small urn-shaped flowers bloom from May to June. The perfect flowers are white to pink, and bear round, fleshy or mealy, bright red to pink fruits called drupes. This smooth, glossy skinned fruit will range from  ¹⁄₄ to  ¹⁄₂ inch in diameter. The fruit will persist on the plant into early winter. Each drupe contains 1 to 5 hard seeds, which need to be scarified and stratified prior to germination to reduce the seed coat and break embryo dormancy. There is an average of 40,900 cleaned seeds per pound.

Subspecies

There are at least five reported subspecies:

Sources do not agree on the list of subspecies, so some of these may be identical, or may be separate species rather than subspecies. See bearberry and manzanita. For a list of reported North American subspecies and varietals, see USDA Plants Profile in "External links" below. For a complete list of related plants see Arctostaphylos.

Chemical constituents

Arctostaphylos uva-ursi contains the glycoside arbutin.

Some constituents such as the hydroquinones are hepatotoxic and in cases of urinary tract infections, other treatment options are recommended.

Uses

The fruit is edible, but bland and mealy.

Smoking

Bearberry is the main component in many traditional North American Native smoking mixes, known collectively as "kinnikinnick" (Algonquin for a mixture). Bearberry is used especially amongst western First Nations, often including other herbs and sometimes tobacco. Some historical reports indicate a "narcotic" or stimulant effect, but since it is almost always smoked with other herbs, including tobacco, it is not clear what psychotropic effects may be due to it alone. For a full discussion of Amerindian smoking mixtures see kinnikinnick.

Cultivation

There are several cultivars that are propagated for use as ornamental plants. It is an attractive evergreen plant in gardens, and it is also useful for controlling erosion.