Persicaria longiseta (Bruijn) Kitag.
Synonym: Polygonum cespitosum
Coefficient of Conservatism: *
Coefficient of Wetness: 0
Wetness Index: FAC
Physiognomy: Ad A-Forb

Polygonum cespitosum of Michigan Flora.

A native of eastern Asia, becoming a weed in disturbed, open areas and along roadsides. Only recently entering the state and not collected until 1978, in Washtenaw Co.

Closely resembles P. maculosa and may grow with it. The bristles at the summit of the ocreae are also long (about equaling the sheath, whereas they are shorter in P. maculosa). Besides the longer bristles and consistently 3-sided achenes, this smartweed has a deeper pink flower color and the inflorescence tends to be more slender and less dense than in most plants of P. maculosa. The latter usually has stronger, more prominent nerves toward the base of the tepals.


Cass County
Iron County
Jackson County
Kalamazoo County
Lenawee County
Oakland County
Washtenaw County
Wayne County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. June 29, 2022.