Annual with an erect to spreading growth habit. Leaves are alternate, cauline, lanceolate to ovate, margins ciliate, leaf bottoms hairy with long appresed hairs, tops glabrous. Leaf measured at 14. 5 cm long and 28 mm wide. Purple spots mid leaf on leaves of some plants, not all. Stems glabrous. Flowers greenish-white in terminal and axillary spikes. Spike measured at 3.5 cm long, flowers measured at 3 mm long. Ocrae lacking bristles (final question in the taxonomic key to genus Polygonum to identify P. lapathifolium in Flora of Alberta).
Habitat is fields, slough margins and low areas.
Height listed in Flora of Alberta to 80 cm, we measured plants to 86 cm tall.
Took the above photos August 18th, low spot in cultivated field, Parklands, about 300 km east of our home in Regina, SK.