Annual herb 10 - 50 cm tall Stem: erect, usually with few opposite branches at 90 degrees to adjacent pairs (decussate), sometimes unbranched, with five to twelve nodes bearing leaves. Leaves: in whorls of three or four, stalkless or nearly so, 1 - 4 cm long, 1 - 4 mm wide, linear to narrow elliptic with a rounded to abruptly pointed tip. Inflorescence: a dense cluster (raceme), 1.5 - 4.5 cm long, 1.2 - 2 cm across, cylindrical with a rounded tip. Flowers: pale rose purple to greenish purple, with three small outer sepals and two petal-like inner sepals (wings). The wings are 4 - 6 mm long, 3 - 4 mm wide at the base, and triangular with a sharply pointed tip. Three petals fused into a tube, shorter than the wings, with one petal fringed. Fruit: an elliptic dehiscent capsule having a 1 mm long appendage (aril) with linear lobes about as long as the slightly wrinkled seed.
Similar species: Polygala cruciata and Polygala verticillata have whorled leaves. Polygala verticillata has flower clusters that are smaller than 7 mm across and leaves with a sharp pointed tip. Polygala cruciata var. aquilonia is distinguished by its wider leaves (3 - 7 mm) and slightly smaller inflorescences (0.7 - 3.5 cm long, 0.7 - 1.5 cm across).
Flowering: July to September
Habitat and ecology: Local in acid sandy soils.
Occurence in the Chicago region: native
Etymology: Polygala comes from the Greek words polys, meaning much, and gala meaning milk, referring to the old belief that milkworts would aid in milk secretion. Cruciata means cross-shaped, referring to the whorls of four leaves.
Erect annual 1-3 dm, sometimes simple, but usually with a few decussate branches; lvs chiefly in whorls of 3 or 4, linear to oblanceolate or narrowly elliptic, 1-4 cm נ1-5 mm, obtuse or rounded, often apiculate; racemes cylindric, 1-6 נ1-1.5 cm, rounded at the summit, usually sessile or nearly so; fls pale rose-purple or greenish-purple; wings deltoid, 3-4 mm wide at base, 4-6 mm long, terminating in a slender cusp 0.5-1.5 mm; 2n=36, 40. Damp or wet soil, marshes, pine-barrens, etc., chiefly but not wholly on the coastal plain; Me. to Fla. and Tex., also in Ky. and from O. and Mich. to Ill. and Minn. July-Sept. (P. ramosior)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Most often in moist sandy soil on the border between a black oak woods and a marsh and usually associated with Gaultheria procumbens. Sometimes in a moister location and infrequent in a moist prairie habitat. Local but usually frequent where it is found.