232 URTICE.E. [ Urtica. 



ORD. 63. URTICE^E. Juss. Nettle Family. 



Flowers monoecious or dioacious, scattered or clustered, or 

 surrounded by a 1-leaved involucre. Perianth of one piece, 

 raembranaceous, lobed, persistent. BARREN FL. Stamens de- 

 finite, inserted into the base of the perianth, and opposite its 

 lobes : anthers curved inwards in aestivation, and often curving 

 backwards with elasticity when bursting FERTILE FL. Ovary 

 simple, free : ovule solitary, erect : stigma 1. Fruit an ache- 

 mum, surrounded by the membranous or fleshy perianth. 

 Embryo straight, curved, or spiral, with or without albumen : 

 radicle superior, and thus remote from the hilum. Trees or 

 shrubs, of almost every part of the world. Leaves alternate, 

 sometimes opposite, with stipules often hispid and stinging, (some- 

 times very powerfully so), or rough. 



1. PARIETARIA. Linn. Wall- Pell itory. 



Perianth 4-fid, inferior. Filaments of the stamens at first in- 

 curved, then expanding with an elastic force. Fruit 1-seeded, 

 enclosed^by the enlarged perianth, (One or more of the cen- 

 tral florets without stamens.) Name from paries, a ivall, from 

 the species frequently growing on old walls. 



Tetrandria. Monogynia. 



1. P. qfficinalis, Linn. Common Pellitory of the wall. 

 Leaves ovato-lanceolate, 3-nerved above the base ; " involucre 

 in two portions, each of about seven segments ; in each portion 

 are three flowers, with one fertile one between them." Wilson. 

 Br. Fl. \. p. 69. E. Fl. v. i. p. 222. E. Bot. t. 597. 



Old walls and waste places. Fl. during the summer months. 1. 

 Stems often procumbent upon the wall, reddish, pubescent. Leaves 

 alternate. Flowers small, hairy, purplish, clustered in the axils of the 

 leaves. " In each portion of the involucre are three flowers apparently 

 fertile," ( Wilson), but of which the central one has only a pistil. 

 The lateral ones have stamens and pistil. Filaments jointed, in which 

 peculiarity exists the elastic property by which the pollen is so copi- 

 ously discharged. This is remarkably the case in a hot summer's day. 

 Fruit black, shining. Pericarp closely investing the seed. 



2. URTICA. Linn. Nettle. 



Barren ft. Perianth single, of four leaves, containing the cup- 

 shaped rudiment of a pistil. Fertile fl. Perianth single, of 

 two leaves. Pericarp 1-seeded, shining. Name; from uro, 

 to burn, in allusion to its stinging property. 



Moncecia. Pentandria. 



1. U. pilulifera, Linn. Roman Nettle. Leaves opposite, 



