634 CANNABINACEAE. Vol. I. 



i. Cannabis sativa L. Hemp. Red-root. Fig. 1555.. 



Cannabis sativa L. Sp. PI. 1027. 1753. 



An annual branching herb, 3°-io° tall, the inner 

 fibrous bark very tough, the branches nearly erect. 

 Leaves divided to the base, the segments lanceolate 

 or linear-lanceolate, acuminate at both ends, sharply 

 and coarsely serrate, 3'-6' long, i'-i' wide; staminate 

 panicles narrow, loose, peduncled,, 3-5' long; pedicels 

 filiform, bracteolate, i"-3" long; pistillate spikes erect, 

 leafy-bracted, 1' long or less in fruit; achene crusta- 

 ceous, ovoid-oblong, about 2" high. 



In waste places, New Brunswick to Ontario and Minne- 

 sota, south to North Carolina, Tennessee and Kansas. 

 Widely distributed in all temperate regions through culti- 

 vation, and occasionally a troublesome weed. Native of 

 Europe and Asia. July-Sept. Gallow-grass. Neckweed. 



Family 11. URTICACEAE Reichenb. Consp. 83. 



Nettle Family. 



1828. 



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

 opposite mostly stipulate simple leaves, and small greenish dioecious, monoe- 

 cious or polygamous flowers, variously clustered. Calyx 2-5-cleft, or of distinct 

 sepals. Petals none. ' Stamens in the staminate flowers as many as the lobes 

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

 anthers reversed in the bud, straightening at anthesis. Ovary superior, i-celled; 

 style simple ; stigma capitate and penicillate, or filiform ; ovule solitary, erect or 

 ascending, orthotropous, or in some genera partly amphitropous. Fruit an 

 achene. Endosperm oily, usually not copious ; embryo straight. ' 



About 40 genera and 550 species of wide geographic distribution. 

 Herbs with stinging hairs. 



Leaves opposite ; both kinds of flowers 4-parted ; achene straight. 

 Leaves alternate ; staminate flowers 5-parted ; achene oblique. 

 Herbs without stinging hairs. 



Flower-clusters panicled or spiked, 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. Urticastrum. 



3. Pilea. 



4. Boehmeria. 



5. Parietaria. 



i. URTICA (Tourn.) L. Sp. PI. 983. 1753. 



Annual or perennial simple or branching herbs, with stinging hairs, opposite 3-7-nerved 

 petioled dentate or incised leaves, and distinct or connate stipules. Flowers very small and 

 numerous, axillary, cymose-paniculate, or glomerate, dioecious, monoecious or androgynous. 

 Staminate flowers with a deeply 4-parted calyx and 4 stamens. Pistillate calyx 4-parted, the 

 segments unequal, the exterior ones usually smaller than the inner; ovary straight; stigma 

 sessile or nearly so; ovule erect, orthotropous. Achene compressed, ovate or oblong, 

 enclosed by the persistent membranous or slightly fleshy calyx. Seed-coat thin ; endosperm 

 little; cotyledons broad. [The ancient Latin name.] 



About 30 species of wide geographic distribution. Type species : Urtica dioica L. 



Perennials, 2°-7° tall ; flower-clusters large, compound. 



Leaves ovate, cordate at base, pubescent. i. U. dioica. 



Leaves lanceolate to ovate-lanceolate, rounded to cordate at base, nearly glabrous. 



2. U. gracilis. 

 Annuals, 6'-3° tall ; flower-clusters small, mostly glomerate. 



Leaves oval to ovate, laciniate-dentate ; plant leafy to the top. 3. U. wens. 



Leaves ovate or lanceolate, or the lower orbicular, crenate ; upper leaves small. 



4. U. chamaedryoides. 



