Galium mollugo is a perennial herb 0.25-1.2 m long, from a branched tap root; spreading by rhizomes (Mersereau and DiTommaso 2003); stems numerous, top more-or-less upright, weak-stemmed from a reclining base, stems smooth to short hairy below, 4-angled.
Leaves in whorls of 6-8 on main stem, 6 on branches, 1-2.5 cm long, about 0.3 cm wide, 1-veined, oblong-linear, usually widest above middle, margin with minute forward-pointing stiff hairs.
Flowers white, 4-parted, 0.2-0.5 cm wide; inflorescence terminal, diffuse, often large branching widely. Pollinated by insects (Mersereau and DiTommaso 2003).
Fruit dry, 2-lobed, smooth, capsule to 0.1 cm long; blooms and fruits June-Aug.
Wetland status: UPL.
Frequency in NYC: Infrequent.
Habitat: Open roadsides, lawns, meadows, fill.
Notes: Produces a number of chemicals that have allelopathic effects (Mersereau and DiTommaso 2003).