Northern Prairie Wildlife Research Center


Home	About NPWRC	Our Science	Staff	Employment	Contacts	Common Questions	About the Site

Northeast Wetland Flora

Field Office Guide to Plant Species

Marshpepper Smartweed
Polygonum hydropiper L.

JPG -- Species Photo JPG -- Distribution Map

Family: Smartweed (Polygonaceae)
Flowering: June-November
Field Marks: The characters that distinguish this species from all other smartweeds are the bristly leaf sheaths, the glandular-dotted, green and often purplish sepals, and the dull (not shiny) achenes.
Habitat: Wet ground.
Habit: Annual herb with fibrous roots.
Stems: Spreading to upright, branched or unbranched, often purple-red, up to 1 1/2 feet tall, smooth.
Leaves: Alternate, simple, linear-lanceolate to ovate-lanceolate, pointed at the tip, tapering or somewhat rounded at the base, without teeth but often wavy-edged, smooth or sometimes short-hairy on the veins beneath, usually dotted, up to 3 1/2 inches long, up to 1 1/4 inches wide, short-stalked; sheaths fringed with short bristles.
Flowers: Several in interrupted racemes, the racemes drooping or arching, up to 3 1/2 inches long.
Sepals: 4, united below, greenish, often tinged with purple and bordered with white, dotted, up to 1/8 inch long.
Petals: 0.
Stamens: 4-6.
Pistils: Ovary superior; style 2- to 3-parted.
Fruits: Achenes lenticular to triangular, ovoid, dull, striate, dark brown to black, up to 1/6 inch long.
Notes: The achenes are eaten by waterfowl.

Previous Species -- Dense-flower Smartweed (Polygonum densiflorum)
Return to Species List -- Group 8
Next Species -- Little Water-pepper (Polygonum opelousanum)

Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
URL: http://www.npwrc.usgs.gov/resource/plants/florane/species/8/polyhydr.htm
Page Contact Information: Webmaster
Page Last Modified: Thursday, 03-Aug-2006 11:39:25 EDT
Menlo Park, CA [caww54]