NETTLE FAMILY 367 



superior, 1-celled, with 1 orthotropous erect ovule; style and stigma 1. Embryo 

 straight. Endosperm oily. Fruit an achene, always enclosed or covered by 

 the calyx. 

 Leaves opposite, toothed, stipulate; hairs stinging; achene flattened. 



Pistillate calyx 4-parted, the segments almost distinct, the inner ones largest. .1. URTICA. 



Pistillate calyx saccate, 2 to 4-toothed at orifice 2. HESPEROCNIDE. 



Leaves alternate, entire, without stipules; hairs not stinging; achene ovoid; pistillate calyx 



tubular, 4-cleft 3. PARIETARIA. 



1. URTICA L. NETTLE. 



Annual or perennial herbs with stinging hairs. Leaves opposite, petioled, 

 3 to 7-nerved, with stipules. Flowers in ours momscious, clustered, the clusters 

 in axillary, often branching spikes. Staminate flower with 4 sepals, 4 stamens 

 and a cup-shaped rudiment of a pistil. Pistillate calyx with the sepals unequal, 

 the exterior smaller than the inner and at length enclosing the flattened achene ; 

 ovary with sessile tufted or almost feathery stigma. Endosperm scanty. (Latin 

 name of the nettle.) 

 Pistillate and staminate flowers in separate spike-like inflorescences; perennial. 



Herbage gray; leaves ovate to lanceolate 1. U. gracilis var. 



Herbage dark green ; leaves broadly ovate, cordate at base 2. U. californiea. 



Pistillate and staminate flowers mixed in the same cluster; herbage dark green; annual. 

 3. U. urens. 



1. U. gracilis Ait. var. holosericea Jepson n. comb. (U. holosericea Nuttall). 

 Stem erect, unbranched, 4 to 10 feet high; leaves long ovate to lanceolate, com- 

 monly green and with scattered bristles above, gray below with a short dense 

 pubescence, coarsely serrate, 3 to 5 inches long; petioles y 2 to 2 inches long; 

 stipules narrowly oblong, mostly acutish, 2 to 6 lines long; flowers (as also in 

 next) sessile in small clusters (glomerules), the clusters in dense simple or 

 somewhat paniculately branched spikes ; pistillate spikes i/G to 2 inches long, the 

 staminate in axils below the pistillate and often twice as long; inner sepals not 

 or scarcely exceeding achene; achene elliptic but acutish at apex and often at 

 base, smooth. 



Along creeks, about damp spots in the hills, in moist valleys or in marshes, 

 common and often abundant; throughout California except in the desert regions; 

 extends north to Washington. Ranges altitudinally from sea-level to 9,800 

 feet in the Sierra Nevada. From the ordinary Eastern U. gracilis the Californian 

 plant differs only in its more abundant (albeit variable) pubescence and some- 

 what more densely flowered spikes, being more like it than the plant of the 

 southern Rocky Mts. (U. gracilenta Greene). In pubescence and in amount of 

 flower production var. holosericea is very variable. It has the following forms : 



Forma greeneii Jepson n. form. Herbage yellowish green; achene with very 

 short and obscure stipe. (Herba flavo-viridis ; achenium stipiti breve). Etna, 

 Siskiyou Co., E. L. Greene, no. 1028. 



Forma densa Jepson n. form. Herbage very gray ; leaves on flowering portion 

 of stem reduced, the paniculate spikes equalling or exceeding them, very num- 

 erous and forming a dense uninterrupted compound panicle. (Herba cana 

 valde; inflorescentia paniculata duplicata densa). Howell Mt., W.L.J., Sept. 

 24, 1893; also lower Sacramento River (Andrus Island). 



Eefs. URTICA GRACILIS Aiton, Hort. Kew. vol. 3, p. 341 (1789). U. holosericea Nuttall, 

 Jour. Phil. Acad. n. s. vol. 1, p. 183 (1847), type loc. near Monterey, Gambel; Jepson, Fl. W. 

 Mid. Cal. p. 147 (1901). 



U. BREWERI Watson, Proe. Am. Acad. vol. 10, p. 348 (1875), type loc. Los Angeles, Brewer, 

 no. 95 (1861). Leaves thin, finely hispid beneath, tuberculately roughened above; panicles 



