Polygonum lapathifolium L.
Persicaria incarnata (Elliot) Small
Persicaria lapathifolia (L.) Gray
Persicaria tomentosa (Schrank) E.P. Bicknell
Polygonum incanum F.W. Schmidt
Polygonum incarnatum Elliot
Polygonum lapathifolium L. ssp. pallidum (With.) Fr.
Polygonum lapathifolium L. var. incanum (F.W. Schmidt) W.D.J. Koch
Polygonum lapathifolium L. var. nodosum (Pers.) Small
Polygonum lapathifolium L. var. ovatum A. Braun
Polygonum lapathifolium L. var. prostratum Wimm.
Polygonum lapathifolium L. var. salicifolium Sibth.
Polygonum nodosum Pers.
Polygonum oneillii Brenckle
Polygonum pensylvanicum L. ssp. oneillii (Brenckle) Hultén
Polygonum scabrum Moench
Polygonum tomentosum Schrank
Nodding Smartweed, Pale Smartweed, Dock-leaved Smartweed
Nodding smartweed is a North American native. The genus Polygonum means ”many knees”—a reference to the swollen, jointed sheaths the are found wherever leaf stems meet the vine.
Identification: Plants are 24-60" (60-152 cm) high, usually upright, sometimes sprawling (the stems aren’t very strong), with green or deep red hairless stems. Leaves are alternate, 1-8" (2.5-20 cm) long. They vary in shape but are typically lance-like, fatter at the base and tapering to a sharp tip. They have tiny, hooklike hairs that make them feel rough. Where each leaf stem meets the main stem, there is a thick sheathlike joint that is characteristic of this genus. Flowers are greenish-white to pink, in columns about ¼-⅜" (6.3-9.5 mm) in diameter and 1-3" (2.5-7.6 cm) long. The clusters may be upright, arched, or drooping. The tiny, individual flowers never actually open.
Polygonum lapathifolium at the University of Wisconsin's Robert W. Freckmann Herbarium
Polygonum lapathifolium at the Lady Bird Johnson Wildflower Center
Polygonum lapathifolium on CalPhotos
Polygonum lapathifolium on the Connecticut Botanical Society's Connecticut wildflowers site
Polygonum lapathifolium on SEINet—the Southwest Environmental Information Network
Polygonum lapathifolium description by Thomas H. Kent, last updated 12 Oct 2018.