Oso manzanita

Description

Arctostaphylos osoensis is a species of manzanita known by the common name Oso manzanita. It is endemic to San Luis Obispo County, California, where it is known from only two occurrences on the northern edge of the Los Osos Valley. This is a spreading shrub reaching at least a meter in height and known to grow over four meters tall. The bark is grayish in color and shreddy. The foliage is dense with shiny, pointed, smooth-edged or toothed green to reddish leaves each up to 3 centimeters long. The inflorescence is a loose bunch of urn-shaped manzanita flowers each about 6 millimeters long. The fruit is a hairless drupe between 0.5 and one centimeter wide containing several rounded seeds. Arctostaphylos is a genus of plants comprising the manzanitas and bearberries. They are shrubs or small trees. There are about 60 species, of Arctostaphylos, ranging from ground-hugging arctic, coastal, and mountain species to small trees up to 6 m tall. Most are evergreen (one species deciduous), with small oval leaves 1–7 cm long, arranged spirally on the stems. The flowers are bell-shaped, white or pale pink, and borne in small clusters of 2–20 together; flowering is in the spring. The fruit are small berries, ripening in the summer or autumn. The berries of some species are edible. Arctostaphylos species are used as food plants by the larvae of some Lepidoptera species including Coleophora arctostaphyli (which feeds exclusively on A. uva-ursi) and Coleophora glaucella. Manzanitas, the bulk of Arctostaphylos species, are present in the chaparral biome of western North America, where they occur from southern British Columbia in Canada, Washington to California and New Mexico in the United States, and throughout much of northern and central Mexico. Three species, the bearberries, A. alpina (alpine bearberry), A. rubra (red bearberry) and A. uva-ursi (common bearberry), have adapted to arctic and subarctic climates, and have a circumpolar distribution in northern North America, Asia and Europe. An unusual association of manzanita occurs on Hood Mountain, in Sonoma County, California, where stands of pygmy forest dominated by Mendocino cypress are found.