This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds. Time of bloom: August to September. Seed-time: September to October.
Range: From Utah and the Wasatch Mountains westward throughout California. Habitat: Waste places, borders of streams.
A larger and stouter plant than either of the common Eastern Nettles, and possessed of vicious stings. Stem erect, unbranched, bristly hairy, frequently attaining to ten feet in height though more commonly four to seven feet tall. Leaves three to six inches long, ovate to lance-shape but obtuse at base, with short, stout petioles and oblong stipules; they are rather thick, hairy on both sides, but especially so on the lower surface. The staminate flowers are in loose, slenderly branching, axillary panicles nearly as long as the leaves; pistillate panicles much shorter and more crowded, the persistent membranaceous calyx-lobe enfolding the achenes. (Fig. 50.)
Cultivation of the ground for the purpose of destroying the perennial roots; or, small areas may be grubbed out. When tillage is impracticable, close and persistent cutting will prevent seeding and starve the roots.
Fig. 50. - Western Nettle (Urtica holosericea). X 1/6.
 
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