Galium obtusum is a perennial herb, stems matted, branched, 20-80 cm long, 4-sided, angles smooth, nodes densely bearded.
Leaves in whorls of 4, 1-3 cm long, 0.1-0.6 cm wide, linear to lance-shaped, tips blunt, margins rough.
Flowers white, 4-parted, 0.2-0.3 cm wide, in clusters of 3-5 at ends of stems; blooms May-July.
Fruit dry, 2-parted capsule, 0.4-0.5 cm wide, slightly warty, only one side developed.
Wetland status: FACW+.
Frequency in NYC: Very infrequent.
Habitat: Wet meadows and thickets.