Galium obtusum Bigelow
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Matted perennial, strict and branched from the base or diffusely branched throughout, 2–8 dm; stems smooth on the angles but densely short-bearded at the nodes; principal lvs in 4’s, linear to lanceolate or oblanceolate, 10–30 × 1–6 mm, obtuse, the margins and the midvein beneath usually ± scabrous or hispid-ciliolate; infls short, almost all terminal, with 3–5 fls on short ascending pedicels, the pedicels in fr 5–10 mm, divaricate, stiff, smooth; fls white, 4-merous, 2–3.5 mm wide, the lobes longer than wide; frs 4–5 mm, ± tuberculate, often only one mericarp developed; 2n=48. Swampy thickets and moist meadows; N.S. and s. Que. to Minn. and S. D., s. to Fla. and Tex. May–July. (G. tinctorium, misapplied) The widespread var. obtusum has the lvs mostly (2)3–5 mm wide, and has consistently bearded nodes. The var. filifolium (Wiegand) Fernald, from s. N.J. to Ga., often near the coast, has lvs mostly 1–2 mm wide, and the nodes are not always bearded.