64 URTICACE^E. Urlica. 



* Beset with stinging hairs : leaves opposite, dentate, stipulate : akene compressed. 



1. Urtica. Sepals 4, distinct, the inner ones largest in the fertile flowers and enclosing the 



akene. 



2. Hesperocnide. Staminate calyx 4-parted; pistillate tubular, unequally 2-4-toothed and 



enclosing the akene. 



* * Unarmed : leaves alternate, entire, without stipules : akene ovoid. 



3. Parietaria. Inflorescence involucrate-bracted. Staminate calyx 4-parted ; pistillate tubular- 



eauipauulate, 4-lobed, enclosing the akene. 



L URTICA, Tourn. NETTLE. 



Flowers monoecious or dioecious, green, clustered in axillary geminate racemes, 

 spikes or loose heads, without bracts : staminate flowers on jointed pedicels, with 

 4 sepals, 4 stamens, and a rudimentary cup-shaped ovary; the pistillate with 4 

 sepals, the 2 outer small and spreading, the inner erect, becoming membranous and 

 enclosing the flattened ovate akene : stigma sessile, capitate, tufted : albumen scanty. 

 Herbs, armed with stinging hairs, with obtusely 4-angled sulcate stems ; leaves 

 opposite, serrate, with distinct lateral stipules ; fruit persistent. 



A wide-spread genus in temperate and subtemperate regions, of 30 or 40 species, about a third 

 American. 



* Perennials, with running rootstocks : inflorescence unisexual; panicles usually 

 exceeding the petioles: stipules large, entire. 



1. U. holosericea, IS r utt. Tall and stout, 5 to 8 feet high, more or less bristly, 

 finely and densely tomentose especially on the lower side of the leaves : stipules 

 membranous, -| inch long, oblong, obtuse or acute ; leaves thick, oblong- to ovate- 

 lanceolate, acuminate, 2 to 4 inches long, rounded or subcordate at base, coarsely 

 serrate, on short stout petioles : staminate flowers in loose slender diffuse panicles 

 nearly equalling the leaves ; pistillate panicles denser and shorter : inner sepals 

 ovate, densely hispid, ^ line long, about equalling the broadly ovate akene. PI. 

 Gambel. 183; Watson, Proc. Am. Acad. x. 349. U. trachycarpa, Weddell, 

 Monogr. 95, & DC. Prodr. xvi 1 . 58. U. dioica, var. obcidentalis, Watson, Bot. 

 King Exp. 321. 



Throughout the State, and eastward to Utah ; especially common in S. California. Nuttall 

 describes the leaves as sometimes (probably the lowest ones) a span long and long-petioled. 



2. U. Breweri, Watson. Tall and stout, grayish with a short somewhat hispid 

 pubescence or nearly glabrous, and with scattered bristles : stipules membranous, 

 oblong-lanceolate : leaves thin, finely pubescent, soon glabrate or roughish above, 

 ovate to oblong-lanceolate, 2 to 6 inches long, acute or acuminate, rounded or 

 slightly cordate at base, coarsely serrate, on slender petioles 1 to 3 inches long or 

 more : flowers in short open panicles scarcely exceeding the petioles : sepals obovate 

 or rounded, obtuse, minutely hispid, nearly a line long and nearly twice longer than 

 the broadly ovate akene. Proc. Am. Acad. x. 348 ; Rothrock, Bot. Wheeler, t. 25. 



Frequent about Los Angeles (Brewer) and ranging eastward to S. Colorado (Wolf) and W. 

 Texas, Siyetow. 



3. IT. Lyallii, Watson, 1. c. Tall, rather slender, more or less pubescent, be- 

 coming nearly glabrous, with scattered bristles : stipules large, membranous, broadly 

 oblong, obtuse ; leaves ovate, somewhat cordate at base, acute, 3 to 6 inches long or 

 more, coarsely serrate, on slender petioles 2 to 4 inches long : flowers in loose slen- 

 der spreading panicles, equalling or shorter than the petioles : sepals broadly ovate 

 or rounded, obtuse, shorter than the broadly ovate akene, which is line long. 



A very large-leaved species, collected in Marin County (Kdlogg) and northward in the Cascade 

 Mountains and at Vancouver Island, Lyall. 



