242 OXXIIIp. URTICACEZ (Rendle), | Urtica. 
Tre IV. PARIETARIEA.—Flowers polygamous in Parietaria. Perianth of 
the % flower 4-partite, of the female flower tubular, 4-lobed, free from the 
ovary. Fruit enclosed in the dry perianth. Annual or perennial herbs (in 
Parietaria), without stinging hairs and with dot-like cystoliths. Leaves 
alternate, entire, exstipulate. Female inflorescence enclosed by bracts. 
Only tropical African genus... fe see ... 14, PARIETARIA. 
Trine V. FORSKOHLEA.— Male flower with a tubular or cup-like perianth 
and one stamen. Female flower with tubular perianth enclosing the achene. 
Herbs or undershrubs without stinging hairs and with dot-like cystoliths. 
Leaves alternate or opposite, generally toothed. Flowers very small, 
generally enclosed within an involucre of bracts. 
Flowers enclosed in a cup-like involucre of bracts and 
generally surrounded by woolly hairs. 
Bracts of the involucre more or less distinct ; stem 
roughly hairy ane BEE ve . 15. ForsKOHLEA. 
Bracts of the involucre united ; stem smooth ... 16. DROGUETIA. 
Flowers not enclosed in a cup-like involucre ... ... 17, AUSTRALINA. 
1. URTICA, Linn. ; Benth. et Hook. f. Gen. PI. ii. 381. 
Flowers moncecious or dicecious in cymose clusters arranged in 
spikes, racemes or panicles. Male flowers: Perianth deeply divided 
into 4 ovate concave lobes which are imbricate in the bud. Stamens 
4; rudimentary ovary cup-shaped. Female flowers: Perianth with 
4 unequal segments, the outer generally much smaller, flat. Ovary 
ovoid bearing a sessile (or more rarely with a short style), penicillate 
stigma ; ovule erect from the base. Achene compressed, enveloped 
in the membranous or sometimes fleshy persistent perianth ; per! 
carp membranous or slightly crustaceous. Seed-coat membranous ; 
albumen scanty ; cotyledons roundish—Annual or perennial herbs, 
sometimes shrubby at the base, with stinging hairs. Leaves opposite, 
petioled, simple, toothed or cut, palmately nerved. Stipules lateral, 
free or connate. Inflorescences unisexual or androgynous, in pairs 
in the leaf-axils ; clusters of flowers with a bract at the base ; flowers 
generally ebracteate. 
Species about 35, widely dispersed throughout the world but especially in 
temperate and subtemperate countries. 
Moneecious ; leaves ovate or elliptic-ovate, 1-1} in. 
long... cee Ses tig a Be Sc ds Us Urens, 
Dieecious ; leaves ovate-cordate, 2-33 in. long ... 2. U. simensis. 
1. U. urens, Linn. Sp. Pl. ed. i. 984. Moncecious, annual, glabrous 
except for the stinging hairs ; stem erect or ascending, 1-2 ft. high, 
branched. Leaves petioled, membranous, ovate or elliptic-ovate, 
base rounded, cuneate or truncate, margin deeply serrate, with 2 
narrowly oblong apical tooth, 3-5-nerved from the base, 1-1} 1- 
long, and about half as wide, sparsely beset with stinging hairs espe- 
cially on the nerves, dotted with cystoliths ; petiole slender, }-3 mM. 
