Perennial herb with a creeping rhizome 20 cm - 1 m tall Stem: upright or ascending, slender, four-angled, unbranched to often many-branched from base, more or less hairy. Leaves: in whorls of four, numerous, 1 - 2.5 cm long, half as wide, elliptic to oval, three-veined, more or less hairy, and firm. Inflorescence: a two- to three-forked, widely spreading cluster of flowers. Flowers: terminating the branches of the inflorescence, distinctly stalked, greenish purple, 2 - 3 mm wide, more or less flat and circular in outline, with four short lobes. Stamens four, alternating with lobes, shorter than corolla. Styles two, short. Fruit: dry, indehiscent, spherical, paired, separating when ripe, one-seeded, bristly.
Similar species: No information at this time.
Flowering: mid-June to mid-September
Habitat and ecology: Common in sandy Black Oak savannas. Also found in partial shade on dune slopes near Lake Michigan.
Occurence in the Chicago region: native
Etymology: Galium comes from the Greek word gala, meaning milk, referring to the plants that are used to curdle milk. Pilosum means "covered with long, soft hair."
Erect or ascending perennial, 2-10 dm, often with many basal branches, otherwise simple to the infl; lvs numerous, in 4's, elliptic to oval, 1-2.5 cm, half as wide, firm, usually 3- nerved; infls terminal and from the upper axils, each divaricately 2-3-forked, the fls terminating the branchlets; fr uncinate-bristly; 2n=22. Dry woods; N.H. to Mich. and Kans., s. to Fla. and Tex. June- Aug. Most of our plants are the northern phase, var. pilosum, with the stem and lvs ±pubescent with straight hairs. The southern phase, var. puncticulosum (Michx.) Torr. & A. Gray, with the stem and lvs ±pubescent with short, upwardly incurved hairs, extends n. to Mo. and on the coastal plain to s. N.J.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Infrequent throughout the lake area in dry, sandy soil, usually associated with black and white oak; rarer in the southwestern part of the state, where it is generally found in rather sandy soil on the crests and slopes of black oak ridges; apparently absent from the Tipton Till Plain.