Annual herb 5 - 25 cm tall Stem: erect, usually with few opposite branches at 90 degrees to adjacent pairs (decussate), sometimes unbranched, with three to six nodes bearing leaves. Leaves: in whorls of three or four, stalkless or nearly so, 1 - 4 cm long, 3 - 7 mm wide, linear to narrow elliptic with a rounded to abruptly pointed tip. Inflorescence: a dense cluster (raceme), 0.7 - 3.5 cm long, 0.7 - 1.5 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 2.5 - 4 mm long, 2.5 - 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: The typical variety of Polygala cruciata has narrow leaves (1 - 4 mm) and slightly larger inflorescences (1.5 - 4.5 cm long, 1.2 - 2 cm across) than this variety.

Flowering: mid July to late September

Habitat and ecology: Local in acidic sandy soils, often on a slight slope between a black oak savanna and a shallow marsh.

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. Aquilonia refers to its northern distribution.

Author: The Morton Arboretum