242 cxxiiid. urticace/e (Rendlc). [Urtica. 



Tribe IV. PARIETARIE.-E. — Flowers polygamoufi in Parictaria. Perianth of 

 the ^ flower 4-portitc, of the female -fiower iuhuUir^ 4:-lobed, free from the 

 ovary. Fruit enclosed in the dry perianth. Annual or perennial herbs (in 

 Parietaria), without .^tingin// hairs and with dot-like cystoliihs. Leaves 

 alternate, entire, exstipulate. Female inflorescence enclosed by bracts. 



Only tio})ical African genus 14. Parietaria. 



Tkihe V. FORSKOHLE/E. — Male flower with a tubular or cup-like perianth 

 and one stamen. Female flower with tubular perianth enclosing the achevc. 

 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 cu))-lik(> involucre of bracts and 

 generally surrounded by woolly hairs. 

 Bracts of the involucre more or less distinct ; stem 



roughly hairy J 5. Forskohli^a. 



Bracts of the'involucre united ; stem smooth ... 10. Droguetia. 

 Flowers not enclosed in a cuji-likc involucre ... ... 17. Australina. 



1. URTICA, Linn. ; Bentli. et Hook. f. Gen. PL iii. 381. 



Flowers niona;cioiis or dioecious in cvniose 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 nmch 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 ; peri- 

 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 disjK^rsed throughout the world but especially in 

 temperate and subtemjierate countries. 



Monoecious ; leaves ovate or elliptic-ovato, 1-1^- in. 



long i. U. urens. 



Dioecious ; leaves ovate-cordate, 2-3i in. long ... 2. U. simensis. 



1. U. urens, Linn. Sp. PL ed. i. 984. Monoecious, 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 a 

 narrowly oblong apical tooth, 3-5-nerved from the base, 1-1| in. 

 long, and about half as wide, sparsely beset with stinging hairs espe- 

 cially on the nerves, dotted with cystoliths ; petiole slender, |-i in. 



