Botanical name: Persicaria glabra Family: Polygonaceae (Buckwheat family)
Synonyms: Polygonum glabrum
Denseflower Knotweed is an annual or perennial herbs with red, ascending, swollen stems, often rooting at the nodes, 5-15 cm long, not hairy. Leaves are oblong-lanceolate to narrowly lanceolate, 14-28 cm long, 3-6 cm wide, minutely pustulate, otherwise usually smooth, sometimes with scattered hairs on nerves of lower surface, leaf stalk 0.5-2 cm long, ocreae tubular, usually 20-30 mm long, apex not ciliate, sometimes with a few small bristles ca. 0.5 mm long. Flowers in open racemes, sometimes in paniculate inflorescences 5-10 cm long, each flower on a jointed pedicel; tepals white or pinkish, 3-4 mm long, sometimes sparsely so, glandular punctate. Nuts dark brown to nearly back, broadly ovoid, biconvex or subtrigonous, 2-2.5 mm long, the surface glossy.
Identification credit: Dinesh Valke
The flower labeled Denseflower Knotweed is ...