MACLOSKIE: URTICACE/E. 331 



Ovary free, i -celled; style i, undivided; ovule i. Fruit -an. achene, with 

 scanty endosperm. 



Species 1,500, in warm and temperate countries. 



KEY TO THE GENERA. 



A. Perianth consisting of 2-5 distinct leaves. Foliage-leaves opposite. 



1. Stinging. Flowers 4-mero us. Achene enclosed in one of the two larger sepals. 



Urtica. 



2. Not stinging, smooth and shining. Flowers mostly 3-merous ; their sepals unequal, all, 



or all but one, small. Achenes partly naked. Leaves of a pair unequal. Adicea (Pilea). 

 A2. Perianth symphyllous, tubular or campanulate in the fertile flowers. Plants not stinging. 



Parietaria. 



i. URTICA Linn. Nettle. 



Leaves opposite, petiolate, serrate or incised, with stinging hairs, and 

 distinct or connate stipules. Flowers 4-merous, in axillary clusters, 

 'dioecious or monoecious or androgynous. Acftenes compressed, enclosed 

 in the persisting calyx. 



Species 30, widely dispersed extratropically. 



i. U. DARWINII Hook. f. 



Stem slender, erect, sparsely pilose, or even glabrous. Leaves mem- 

 branaceous, ovate-acuminate, coarsely crenate-serrate, rounded at base, 

 3-nerved, finely punctate, puberulous ; petiole slender ; stipules linear- 

 oblong, subacute. Flowers glomerate, in slender, setose, interrupted 

 spikes longer than the petiole. (Larger flowers and achenes than U. 

 dioica. ) 



Chonos Archip. 



2. U. DIOICA Linn. 



Root perennial. Stem erect, the whole plant stinging or smooth. Leaves 

 ovate-acuminate to ovate-lanceolate, serrate, cordate or rounded at base ; 

 stipules in pairs between the petioles. Spikes in pairs, mostly dioecious, 

 much branched, exceeding the petiole, pendulous in fruit. 



(N. Temperate zone, fig. in Brit. & Br. i, 531) ; Magellan. (Dusen.) 



3. U. MAGELLANICA Poir. 



Stem stout, erect, hispid. Leaves subcoriaceous, rugose, ovate to ovate- 

 lanceolate, acuminate, basicordate, acutely serrate-dentate, setose on both 

 sides; stipules linear-oblong, acute. Glomerules setose, in interrupted 

 spikes, shorter than the petioles or longer. 



