Threadleaf milkwort

Herbs annual, single-stemmed, 1.5–3.5(–5) dm, unbranched or branched distally; from slender taproot, sometimes becoming fibrous root cluster. Stems erect, glabrous. Leaves whorled, at least proximally, to alternate distally; sessile or subsessile; blade narrowly obovate to linear-spatulate proximally, linear to filiform distally, 3–30 × 0.5–1(–2.5) mm, base cuneate, apex acute, surfaces glabrous. Racemes spikelike, narrowly cylin­dric, 0.5–6 × 0.2–0.4 cm; peduncle 0.7–3 cm; bracts deciduous, ovate to lanceolate-ovate. Pedicels 0–0.5 mm, glabrous. Flowers white or greenish white, 1.5–2.8 mm; sepals ovate to elliptic, 0.6–1.1 mm; wings elliptic or obovate, 1.5–2.6 × 0.8–1 mm, apex obtuse to bluntly rounded; keel 1.3–2.5 mm, crest 2-lobed, with 2 or 3 lobes on each side. Capsules ellipsoid to oblong, 1.7–2.2 × 1–1.5 mm, margins not winged. Seeds 1.5–2 mm, glabrous; aril 1 mm, lobes 1/2 length of seed.

Flowering spring–summer. Sandhills, dry to xeric pine-oak woodlands; 0–100 m; Ala., Fla., Ga., Miss.

Polygala leptostachys is most common in Florida and rare elsewhere in its range.