260 



URTICACE^. 



[Diclinous Exogens. 



Order LXXXIV. URTICACE^.— Nettleworts. 



Urtice^, Juss. Gen. 400. (1789) ; Gaudichaud in Freyc. Voyage, p. 503. (1826) ; Bartl. Ord. Nat 105. 



Urticacese, Endlich. Prodr. Nor/. 37 ; Gen. xciv. ; Meisner, p. 348. 

 DixGso?>ii.—Urtical Exogens, with small flat stipules, limpid juice, a solid erect ovide, a 

 straight albuminous embryo, and superior radicle. 

 Trees, shnibs, or herbs ; never milky. Leaves alternate, usually covered either with 

 asperities or stinging hairs, \At\\ membranous stipules, which are deciduous or con- 

 volute in vernation. Flowers herbaceous, mconspicuous, S ?? (occasionally Q 



Fig. CLXXVI. 



Fig. CLXXV. 

 mtermixed) scattered, or clustered, or in catkins, or close heads. Calyx membranous, 

 lobed, persistent. $ Stamens definite, distinct, inserted into the base of the calyx, 

 and opposite its 

 lobes ; anthers 

 often curved m- 

 wards in aestiva- 

 tion, and turned 

 backwards with 

 elasticity when 

 bursting. $ Ov- 

 ary superior, simple ; ovule solitary, 

 erect ; stigma simple, fringed. Fruit 

 a simple indehiscent nut, siu'rounded 

 either by the membranous or fleshy 

 calyx. Embryo straight, ^^dth fleshy 

 albumen ; cotyledons flat ; radicle 

 superior. 



Nettleworts, as now cu'cumscribed, consist almost entu'ely of rough-leaved plants, which, 

 although they occasionally acquu'e the statm'e of trees, have nevertheless little more 

 than a herbaceous textm'e, theu' wood bemg remarkable for its lightness, sponginess, 

 and profusion of cellular tissue. Theu- great distinction consists in their having a 



Fig. CLXXV.— 1. Branch of Procris splendens; 2. cluster of male and female flowers ; 3. a male 

 flower about to expand ; 4. the same expanded . 



Fig. CLXXVI.— Parietaria ofiBcinalis ; one of the lenticular fruits both whole and di\dded perpendi- 

 cularly to show the embrj'o. 



Fig. CLXXVIl. — 1. A section of the ovary of Urtica dioica ; 2. the same when ripe, after the embryo 

 is developed. 



Fig. CLXXVIl. 



