Whorled milkwort, polygale verticillé

Polygala ambigua Nuttall; P. pretzii Pennell; P. verticillata var. ambigua (Nuttall) Alph. Wood; P. verticillata var. dolichoptera Fernald; P. verticillata var. isocycla Fernald; P. verticillata var. sphenostachya Pennell

Herbs annual, single-stemmed, 0.5–3(–4) dm, usually branched distally; from slender taproot. Stems erect, sometimes slightly glaucous, glabrous. Leaves usually whorled proximally, sometimes whorled to inflorescence, opposite to alternate distally, rarely alternate throughout; sessile or subsessile, petiole rarely to 1 mm; blade sometimes linear-spatulate proximally, usually linear, linear-oblong, -elliptic, or -lanceolate distally, (5–)10–20(–30) × 0.5–5.5 mm, base cuneate to acute, apex acute to acuminate, surfaces glabrous. Racemes nearly spike­like, conic to cylindric-conic, 0.5–5 × 0.2–0.6 cm, some­times interrupted proximally, with some proximal fruits persistent below gap; peduncle to 9 cm (usually elongate); bracts deciduous, subulate to lanceolate. Pedicels 0.2–1(–2) mm, glabrous. Flowers white or with greenish or pinkish tinge, sepals sometimes purplish or whitish, 1–2.2(–2.6) mm; sepals ovate or elliptic to lanceolate, 0.5–1.6 mm, ciliate; wings suborbiculate, ovate, elliptic, or obovate, 1–2.6 × 0.8–2.5 mm, apex obtuse to bluntly rounded; keel 1.2–1.8 mm, crest 2-parted, with 1 or 2 lobes on each side. Capsules subglobose or broadly ellipsoid to ovoid, 1.3–2.4 × 0.7–2.2 mm, margins not winged. Seeds 1.2–2.2 mm, pubescent; aril 0.5–1 mm, lobes 1/3–1/2 length of seed. 2n = 34.

Flowering spring–fall. Meadows, prairies, open woodlands, sand dunes, old fields, open places (limestone glades, railroad rights-of-way, rock quarries); 0–2100 m; Man., N.B., Ont., Que., Sask.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., W.Va., Wis., Wyo.

Varieties of Polygala verticillata have been recognized; they co-occur and intergrade, suggesting that they are polymorphisms not worthy of taxonomic recognition.