Orange milkwort

Pilostaxis lutea (Linnaeus) Small

Herbs biennial or short-lived perennial, single- or multi-stemmed, 0.6–5 dm, unbranched or branched distally; from taproot or fibrous root cluster. Stems erect, sometimes laxly so, to nearly decumbent, glabrous. Leaves usually with basal rosette; alternate; sessile or subsessile, or with narrow petiolelike region to 1–2 mm; basal blade obovate, oblanceolate, or spatulate, cauline becoming narrowly ovate or nearly linear distally, basal to 60 × 20 mm, cauline to 40 × 10 mm, succulent, base cuneate, apex bluntly rounded to obtuse or acute, especially distally, surfaces glabrous. Racemes capitate, 0.8–3.5(–4) × (0.8–)1.2–2 cm; peduncle 3–10 cm; bracts deciduous, narrowly lanceolate. Pedicels winged, 1.5–2.8 mm, glabrous. Flowers usually bright orange, rarely yellow-orange, usually drying pale yellow, 4.5–6 mm; sepals decurrent on pedicel, ovate, 1.2–2 mm, ciliolate; wings elliptic, 5–7.5 × 2.7–3.6 mm, apex acuminate to abruptly cuspidate, partially involute; keel 3.5–6 mm, crest 2-parted, with 2–4 lobes on each side, each lobe entire or divided. Capsules broadly ellipsoid to obovoid, 1.2–2.3 mm, margins not winged. Seeds 1–1.6 mm, pubescent; aril 0.5–1.6 mm, lobes 1/2 to subequal length of seed. 2n = 64, 68.

Flowering spring–fall (nearly year-round). Moist to wet soils (at least seasonally), open fields, savannas, pine flatwoods, sandy mixed pine-hardwoods, bogs, poco­sins, pond margins; 0–200(–300) m; Ala., Del., Fla., Ga., La., Md., Miss., N.J., N.Y., N.C., Pa., S.C., Va.

A single lemon-yellow flowered plant of Polygala lutea has been reported from Brunswick County, North Carolina (R. R. Smith and D. B. Ward 1976); populations elsewhere may also produce yellow or yellow-orange flowers. Smith and Ward also reported that a possible hybrid with P. rugelii had over 65% apparently non-functional pollen grains. DNA analysis of the nrITS region (J. R. Abbott, unpubl.) found the hybrids to be polymorphic at all of the bases that differed between the parents; coupled with their rarity in the landscape despite common co-occurrence with the parents, this supports the hypothesis that they are F1 hybrids rather than established introgressives.