Salix uva-ursi

S. uva-ursi is a prostrate subshrub reaching in height. It forms dense compact clonal mats by layering. The bark of the stems, which trail along the ground, may be red-brown, grey-brown, or yellow-brown, and glabrous. Bark on newer branches may be yellow-green or yellow-brown, glabrous or pubescent. The leaves are ovate to broadly obovate or elliptic, 4-23 mm long by 3.5-10 mm wide. The leaf margins can be entire, serrulate or crenulate. The abaxial surface is glaucous and usually glabrous. The adaxial surface is glossy and usually glabrous. The inflorescences of S. uva-ursi are catkins, with male and female catkins being produced on separate plants. The pistillate (female) catkins stand erect among the leaves and are densely flowered, slender to subglobose in shape, and 11-47 mm long (expanding to -55 mm when fruiting) by 6-10 mm wide. In New Hampshire and populations further north, S. uva-ursi is known to hybridize naturally with S. herbacea, producing the hybrid species Salix × peasei. == Distribution and habitat ==

S. uva-ursi is restricted to arctic, sub-arctic, and alpine regions of northeastern North America. It is found in western Greenland; Saint Pierre and Miquelon; and Nunavut, Nunavik, Newfoundland and Labrador, and Nova Scotia in Canada. At the southern extent of its range, small populations grow in the high peaks of Maine, New Hampshire, Vermont, and New York. It may be found at elevations from near sea-level to . It grows in dry or moist exposed sites in calcareous, serpentine, dioritic, or granitic soils. It often becomes established in cracks in rocks or boulders, but may also grow on sandy beaches or in snowbeds. == Conservation status ==

S. uva-ursi is categorized as a secure (G5) species globally by NatureServe. It is designated as an imperiled species in the southern extent of its range. The table below lists the subnational conservation statuses for each Canadian Province and US State in which it occurs. The slow-growth rate of this species and its sporadic reproduction hinders its ability to compete with other plant species in milder climates. On the high peaks of New York and New England, it is particulary threatened by trampling due to hiker traffic. ==References==