Polygonum glaucum is an annual herb to 30 cm long, prostrate but branch tips upturned, very pale gray-green, leaf sheaths encircling nodes, dark reddish-brown, the margin whitish, bristle-fringed, 0.7-1.0 cm.
Leaves alternate, lance-shaped 1-3 cm long, 0.2-0.8 cm wide.
Flowers pale pink-white, tepals with green midrib, 0.2-0.4 cm, in small axillary clusters; blooming and fruiting July-Oct. (Hough 1983)
Fruit dry, an achene, shiny, blackish, to 0.4 cm long, 0.2 cm wide.
Wetland status: FACU.
Frequency in NYC: Rare (Global status G3, very rare; NYS S3 rare).
Habitat: Sand of back dune areas.