Flora of the Palouse Region 57 



87. URTICA. 



Annual or perennial simple or branching herbs with stinging 

 hairs: leaves opposite, 3-7-nerved, petioled, dentate or incised, 

 with distinct or connate stipules: flowers very small and numer- 

 ous, dioecious, monoecious or androgynous: staminate flowers 

 with a deeply 4-parted calyx and 4 stamens: pistillate flowers with 

 a 4-parted calyx, the exterior segments of which are usually 

 smaller than the inner: ovary straight: akene compressed, ovate 

 or oblong, enclosed by the persistent membranous or slightly 

 fleshy calj r x: endosperm scanty. 



Leaves soft-pubescent on both sides. U. holosericea. 



Leaves quite glabrous above, somewhat pubescent beneath. 



U. LYALLH. 



U. holosericea Nutt. Tall, 2-3 m. high, usually somewhat bristly, densely 

 soft-pubescent throughout: leaves ovate-lanceolate, acuminate, subcordate, 

 coarsely and evenly dentate, velvety pubescent beneath, 8-16 cm. long; 

 petioles short: staminate flowers in loose narrow panicles shorter than the 

 leaves: pistillate panicles denser, in the axils of the uppermost leaves. Var- 

 iable; common along Snake River, also on Union Flat and in the Thatuna 

 Hills. 



U. lyallii Wats. Verymuchlikethepreceding,butnotsotall, i-2in.high: 

 stem merely bristly or glabrous: leaves broadly ovate, cordate, very coarsely 

 dentate, green and usually glabrous above, pubescent or glabrous beneath. 

 Infrequent in moist places. 



88. PARIETARIA. 



Annual or perennial diffuse or erect herbs without stinging 

 hairs: leaves alternate, entire, 3-nerved, petioled, without stipules: 

 flowers axillary, glomerate, polygamous, iuvolucrate by leafy 

 bracts: calyx of the staminate flowers 4-parted or of 4 distinct 

 sepals: fertile flowers with a tubular or campanulate 4-lobed calyx 

 surrounding the ovary: akene enclosed by the withering-persistent 

 calyx. 



Leaves rounded or cuneate at base: bracts equalling the flowers. 



P. DEBIUS. 

 Leaves attenuate-acute at base: bracts exceeding the flowers. 



P. PENNSYLVANIA. 



P. debilis Forst. Stems slender, pubescent, simple or branched at base, 

 weak, S-20cm. long: leaves ovate, obtuse, rounded or cuneate at base, 4-12 

 mm. long, rough-hairy above; petioles short: flowers few in each cluster: 

 bracts oblong-linear, 1-2 mm. long, scarcely longer than the flowers: akenes 

 shining gray, 1 mm. long. Crevices of basalt cliffs near Lewiston. 



P. pennsylvanica Muhl. Very similar to the above: leaves lanceolate, 

 attenuate-acute at base, 2-6 cm. long: bracts much exceeding the flowers, 

 3-5 mm. long. Basalt crevices at Almota and Wawawai. 



