MORACEAE. 



103 



Conocephalus violaceus (Blanco) Merrill, Violet Coxocephalus, of the 

 Philippine Islands, a fine plant of which existed at Bellevue in 1914, is a 

 purplish-violet, glabrous vine, climbing by aerial roots, with long-petioled, 

 elliptic, obtuse leaves 6'-10' long, the minute, 4-parted, greenish flowers in 

 panicled heads about 3" in diameter. [Procris violacea Blanco.] 



Family 3. URTICACEAE Reichenb. 



Nettle Family. 



Herbs (some tropical species shrubs or trees), with watery sap, mostly 

 stipulate simple leaves, and small greenish dioecious, monoecious or polyg- 

 amous flowers, variously clustered. Calyx 2-5-cleft, or of distinct sepals. 

 Petals none. Stamens in the staminate flowers as many as the lobes or seg- 

 ments of the calyx (sepals) and opposite them, the filaments inflexed and 

 anthers reversed in the bud, straightening at anthesis. Ovary superior, 

 1-celled; style simple; ovule solitary, erect or ascending, orthotropous, or in 

 some genera partly amphitropous. Fruit an achene. Endosperm oily, 

 embryo straight. About 40 genera and 550 species of wide distribution. 



Herbs with stinging hairs. 

 Herbs without stinging hairs. 



Flower-clusters not involucrate ; leaves mostly opposite. 

 Pistillate calyx 3-parted or of 3 sepals. 

 Pistillate calyx 2-4-toothed or entire. 

 Flower-clusters involucrate by leafy bracts ; leaves alternate. 



1. Urtica. 



2. Pilea. 



3. Boehmeria. 



4. Parietaria. 



1. URTICA [Tourn.] L. 

 Herbs, with stinging hairs, 3-7-nerved petioled dentate or incised leaves, 

 and distinct or connate stipules. Flowers small and numerous, axillary, cymose- 

 paniculate, spicate or glomerate, dioecious, monoecious or androgynous. Stami- 

 nate flowers with a deeply 4-parted calyx and 4 stamens. Pistillate calyx 4- 

 parted, the segments unequal ; ovary straight ; stigma sessile or nearly so ; ovule 

 erect, orthotropous. Achene compressed, enclosed by the calyx. Seed-coat thin ; 

 endosperm little; cotyledons 

 broad. [The ancient Latin 

 name.] About 30 species of 

 wide distribution. Type 

 species: Urtica dioica L. 



Spikes short, the staminate 

 and pistillate flowers inter- 

 mixed. 1. U. urens. 



Spikes long, the upper stami- 

 nate, the lower pistillate. 



2. C/. membranacea. 



1. Urtica urens L. 



Stinging Nettle. Small 

 Nettle. (Fig. 119.) An- 

 nual, stem 6-18' high, sting- 

 ing-bristly. Leaves thin, 

 glabrous or very nearly so, 

 elliptic, oval or ovate, deeply 

 incised or sometimes doubly 

 serrate, 3-5-nerved, f'-3' 

 long, slender-petioled ; stip- 

 ules short ; flower-clusters 

 oblong, short, rather dense. 



