NETTLE FAMILY. 531 
Herbs with stinging hairs. : 
Leaves opposite; both kinds of flowers 4-parted; achene straight. 1. Urtica. 
Leaves alternate; staminate flowers 5-parted; achene oblique. 2. Urticastrum. 
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. 
r URTICA L, 
. Adicea. 
. Boehmeria. 
. Parietaria. 
Aw 
Spa pinoosae use: 
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 an- 
drogynous. 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; 
oyary straight; stigma sessile or nearly so; ovule erect, orthotropous. Achene compressed, 
oyate 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. 
Perennials, 2°-7° tall; flower-clusters large, compound. 
Leaves ovate, cordate at base. 
Leaves laciniate, rarely cordate. 
1. U. diotca, 
2. U. gracilis. 
Annuals, 6'-23s° tall; flower-clusters small, mostly glomerate. 
Leaves oval, laciniate-dentate; plant leafy at the top. 3. U. urens. 
Leaves ovate or lanceolate, crenate; upper leaves very small. 4. U. chamaedryotdes. 
1. Urtica dioica I, Stinging or Great 
Nettle. (Fig. 1263.) 
Urtica dioica I,. Sp. Pl. 984. 1753. 
Perennial, densely beset with stinging hairs, 
stem rather stout, 2°—4° tall, puberulent above. 
Leaves thin, ovate, long-petioled, acute or acu- 
minate at the apex, cordate at the base, sharply 
or incisely serrate with triangular or lanceolate 
acute teeth, pubescent beneath, 3-5-nerved, 3/— 
5’ long, 1-3’ wide; petioles very slender, shorter 
than the blades; stipules lanceolate; flower- 
clusters large, compound, cymose-paniculate; 
flowers dioecious or androgynous. 
In waste places, Nova Scotia to Ontario and Min- 
nesota, south to South Carolina and Missouri. 
Naturalized from Europe. Native also of Asia. 
Plant lower, stouter and much more stinging than 
the following species. July—Sept. 
iy 
2. Urtica gracilis Ait. Slender Nettle. 
(Fig. 1264.) 
Urtica gracilis Ait. Hort. Kew. 3: 341. 1789. 
Perennial, sparingly armed with stinging 
hairs, stem usually slender, erect, simple or with 
few erect branches, 2°-7° tall. Leaves’ lanceo- 
late or ovate-lanceolate, slender-petioled, long- 
acuminate at the apex, narrowed or sometimes 
rounded at the base (rarely subcordate), sharply 
serrate, 3-5-nerved, sparingly pubescent, 3/-6/ 
long, 12/-1}4’ wide; petioles shorter than the 
blades, usually bristly; stipules lanceolate; 
flower-clusters compound, smaller than those of 
the preceding species, but commonly longerthan 
the petioles; flowers dioecious or androgynous. 
In dry soil, Nova Scotia to British Columbia, 
south to North Carolina, Louisiana and Kansas. 
June-Oct. 
