Galium asprellum is a perennial, spreading, clambering, stems 0.5-1.8 m long, weak, much branched, often matted, 4-angeled with tiny hooks lining angles.
Leaves in whorls of 4-6, narrowly elliptic, widest above middle, to 2 cm long, 0.6 cm wide, tip pointed, margins rough.
Flowers white, radially symmetrical, petal lobes 4; inflorescences of small branched clusters near ends of stems; blooms and fruits May-Aug.
Fruit dry, a smooth capsule 0.2 cm wide.
Wetland status: FACW+.
Frequency in NYC: Very infrequent.
Habitat: Wet woods, thickets, soil pH 5-7. Tolerant of shade (USDA, NRCS 2006).