Galium circaezans is a perennial herb 20-60 cm tall, erect or ascending, stem 4-angled, wiry, smooth to finely hairy, simple to stiffly branched from base.
Leaves in whorls of 4, 2-5 cm long, 1-2.5 cm wide, elliptic, often densely hairy, tip blunt, 3-5 major veins.
Flowers greenish-purple, minutely hairy, radially symmetrical, petal lobes 4, pointed at tips; flowers stalkless, in sparsely branched clusters near ends of stems; blooms June-July.
Fruit dry 2-parted capsules, hairy, 0.3 cm, often with a small, fleshy attachment (elaiosome). These usually considered to be adaptations for ant dispersal.
Wetland status: UPL.
Frequency in NYC: Very infrequent.
Habitat: Dry woods, thickets.
Notes: Dispersal to and establishment in new sites in successional forest, contiguous to old regrowth stands has been calculated at a rate of 1.50 m/yr. (Matlack 1994).