532 



URTICACEAE. 

 3. Urtica urens L. Small Nettle. (Fig. 1265.) 



Urtica urens L. Sp. PI. 984. 1753. 



Annual, stem rather stout, 6 / -iS / high, 

 ascending or erect, it and its slender 

 branches stinging-bristly. Leaves thin, 

 glabrous or very nearly so, elliptic, oval or 

 ovate in outline, deeply incised or some- 

 times doubly serrate, with acute, ascend- 

 ing or spreading teeth, 3-5-nerved, ob- 

 tuse at both ends, or acutish, i'-3' long, 

 slender-petioled; petioles often as long as 

 the blades; stipules short; flower-clusters 

 oblong, rather dense, mostly shorter than 

 the petioles; flowers androgynous. 



In waste places, Newfoundland to northern 

 New York, New Jersey and Florida. Also 

 on the Pacific Coast. Naturalized from Eu- 

 rope. May-Sept. 



Urtica chamaedryoides Pursh. Weak Nettle. (Fig. 1266.) 



Urtica chamaedryoides Pursh, Fl. Ani. Sept. 

 113. 1814. 



Annual, sparingly stinging-bristly but 

 otherwise nearly or quite glabrous, stem very 

 slender, weak, ascending, simple or branched, 

 6 / ~3 long. Leaves slender-petioled, thin, 

 crenate-dentate, the lower broadly ovate or 

 orbicular, obtuse at the apex and usually cor- 

 date at the base, J^'-i^' wide, the upper 

 ovate or lanceolate, acute or acuminate at the 

 apex, rounded or narrowed at the base, the 

 uppermost very small; stipules lanceolate- 

 subulate; flower-clusters small, glomerate, 

 shorter than the petioles; flowers androgy- 

 nous. 



In thickets, Kentucky to Arkansas, south to 

 Georgia and Texas. April-Aug. 



2. URTICASTRUM Fabr. Enum. 204. 1759. 

 [LAPORTEA Gaud, in Freyc. Voy. Bot. 498. 1826.] 



Perennial herbs, armed with stinging hairs, the leaves broad, alternate, serrate, petioled, 

 the flowers monoecious or dioecious, sessile in loose axillary compound cymes. Staminate 

 flowers in our species with 5 imbricated sepals, 5 stamens and a rudimentary ovary. Pistil- 

 late flowers with 4 unequal sepals, the outer i or 2 minute, an oblique or nearly straight com- 

 pressed ovary and a subulate slender persistent style; ovule erect. Acheue very oblique, 

 flat, reflexed. Seed-coat membranous. Endosperm scanty or wanting. [Latin, star nettle.] 



About 25 species, mostly of tropical distribution, only the following North American. 



