Polygonum aviculare is a weedy taprooted annual herb to 10 (20) cm, freely branched, prostrate or sprawling to almost erect; nodes with membranous sheaths (ocreae) 0.4-0.8 cm, becoming tattered strips; node sheath membranous, becomng shredded.
Leaves alternate, of several sizes, early leaves larger, 2.5-6 cm long, 0.4-1.5 cm wide, lance-shaped, later leaves and those of inflorescence about 1/3 as large, blade blue-green, jointed at base,.
Flowers green with white or pink margins, to 0.4 cm when mature, petal lobes longer than tube (corolla divided to below middle), tips flat, in axils; blooming and fruiting June-Nov. (Hough 1983). Fruit an achene, dark brown, to 0.3 cm, very finely warty.
Wetland status: FACU .
Frequency in NYC: Occasional.
Habitat: Open disturbed areas, abused lawns, ball fields, path edges, very tolerant of compaction, disturbance.
Note: Usually not in natural areas.