Taxonomy
Family: Urticaceae
Habitat
Moist woods and floodplains, springy areas.
Associates
Distribution
Quebec west to MN, south to FL, LA, and OK.
Morphology
Monoecious or dioecious annual to 50 cm, with smooth and pellucid (translucent) stems and leaves; leaves opposite, scarcely shiny, ovate, to 12 cm, serrate to crenate-serrate, cuneate to rounded at the base on long petioles; flowers borne in cymes from the middle and upper leaf axils; calyx persistent, deeply lobed, the lobes about equal; calyx of male flowers 4-parted; stamens 4; calyx of female flowers 3-parted; stigma sessile; achenes dark purple or dark olivaceous to nearly black, pale-margined, irregularly elevated on the sides, broadly ovate, 1.3-2 mm long and 70-85% as wides; seeds tuberculate.
Notes
Flowers July to October
Wetland indicator: FACW
Very similar to Pilea pumila (L.) A. Gray which has leaves that are more translucent and shiny and achenes that are green to yellowish and usually marked with purple on the sides (vs. dark purple to dark greenish-black to black with pale margins). Probably less common than P. pumila but not necessarily rare.
References
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY
Michael Hough © 2009 |