232 URTICE.i:. [ Urtica. 



Ord. 03. URTICEiE. Juss. Nettle Family. 



Flowers monoecious or dioecious, scattered or clustered, or 

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

 membranaceous, 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- 

 nium, 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 ivorld. Leaves alternate, 

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

 times very powerfully so), or rough. 



1. Parietaria. Linn. Wall-Pellitory. 



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 icall, from 

 the species frequently growing on old walls. 



Tetrandria. Monogynia. 



1. P. officinalis, 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. 1. p. 69. E. Fl. v. i. p. 222. E. Bot. t. 597. 



Old walls and waste places. Fl. during the summer months. %. — 

 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 b) r 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 fl. 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 Kettle. Leaves opposite,- 



