Biennial herb 10 - 45 cm tall
Leaves: alternate, spaced less than 1 cm apart. Lower leaves are 1 cm long and inversely egg-shaped or spoon-shaped. Middle and upper leaves 1 - 3 cm long, 2 - 7 mm wide, inversely egg-shaped and linear to oblong with a rounded to blunt or pointed tip.
Inflorescence: an open cluster (raceme), 2 - 10 cm long, narrow.
Flowers: rose purple to white with three small outer sepals and two petal-like inner sepals (wings) 4 - 6 mm long. The three petals are fused into a tube shorter than the wings, and one petal is fringed. There are also a few self-pollinating flowers that remain closed (cleistogamous) and arise from a narrow underground raceme.
Fruit: a dehiscent capsule, 3 - 4 mm long, pale, egg-shaped, having softly hairy and elliptic seeds with a conspicuous appendage (aril).
Stems: many, ascending, unbranched at flowering but branching later.
Similar species: Polygala polygama, Polygala incarnata, Polygala paucifolia, Polygala sanguinea, and Polygala senega all have alternate leaves. Polygala paucifolia is a creeping perennial with flowers longer than 11 mm. Polygala incarnata and Polygala sanguinea each have a single stem. Polygala senega has white flowers in dense clusters.
Flowering: late May to early August
Habitat and ecology: Sandy black oak savannas, sandy open areas, dry gravelly hill prairies, and sandy soils near Lake Michigan.
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. Polygama means "having both bisexual and unisexual flowers."
Author: The Morton Arboretum
Plants of this species vary greatly, from erect, from a decumbent or ascending base with only terminal spikes, or sometimes with a few lateral branches of cleistogamous flowers, to widely spreading with terminal spikes and many lateral branches with cleistogamous flowers. The latter extreme form we have from Lagrange County; it is variety ramulosa Farwell (Amer. Midland Nat. 11: 63. 1928). In dry or moist sandy places in black or black and white oak woods, sandy knolls, and in moist interdunal flats. Our specimens are mostly from northwest of the Wabash River.
Biennial; stems clustered, decumbent, glabrous, 1-2.5 dm, simple at anthesis, later sparingly branched; lowest lvs spatulate to obovate, 1 cm; cauline lvs linear- oblanceolate to oblong-oblanceolate, 1-3 cm נ2-7 mm, obtuse to subacute; raceme loose and open, 2-10 cm; fls rose-purple to white; wings obovate, 4-6 mm, exceeding the cor; cleistogamous fls secund in slender subterranean racemes; 2n=56. Dry, usually sandy soil; Me. to Mich. and Minn., s. to N.J., w. Va., O., Ind., and Io.; also along the coastal plain from e. Va. to Fla. and Tex. The northern plants have a slightly denser raceme than the southern and are often distinguished as var. obtusata Chodat.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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