Polygonum oxyspermum subsp. raii
Feddes Repert. Spec. Nov. Regni Veg. 68: 188. 1963.
Leaves: ocrea not prominently veined, 7–10 mm, distal part disintegrating, nearly completely deciduous; blade bluish green, elliptic, 3.5–5 times as long as wide. Flowers: perianth (3.5–) 4–5 mm; tepals overlapping, green with white or pink margins, obovate, apex flat, flared. Achenes with apex exserted 0.5–1.3 (–1.8) mm from perianth, (3.5–) 4–5 mm, 1.3–1.6 times as long as wide, ± smooth or finely striate-tubercled. 2n = 40.
Phenology: Flowering Jul–Oct.
Habitat: Coastal beaches, dunes, and shores
Elevation: 0-10 m
Introduced; St. Pierre and Miquelon, N.B., Nfld. and Labr. (Nfld.), N.S., P.E.I., Que., Maine, Europe
Some sources consider subsp. raii to be native in North America.
"/2" is not declared as a valid unit of measurement for this property.