Tall pine-barren milkwort

Pilostaxis cymosa (Walter) Small; Polygala attenuata Nuttall

Herbs biennial, usually single-stemmed, 4–12 dm, usually unbranched proximal to inflo­rescences; from fibrous root cluster. Stems erect, glabrous. Leaves with persistent, largebasal rosette, sometimes with­ered at anthesis, brown leaves usually present; alter­nate; sessile or subsessile; basal blade linear-lanceolate to linear, (30–)35–70(–140) × 2–7 mm, cauline blade abruptly reduced to bracts of inflorescence, base obtuse, apex acute, obtuse, or rounded, surfaces glabrous. Racemes in cymose panicles, ± flat-topped, 5–11 × 6–20 cm; each stem with to 150 racemose branches, 2–5 × 1–1.5 cm; central ones nearly sessile, lateral ones with peduncle to 3 cm; bracts persistent, narrowly lanceolate-ovate. Pedicels winged, 2–4 mm, glabrous. Flowers bright yellow, becoming pale yellow to green on drying, 4.5–6.4 mm; sepals decurrent on pedicel, ovate to lanceolate-ovate, (1–)1.5–3.2 mm, sometimes sparsely ciliolate; wings elliptic to obovate or oblanceolate, (2–)4–6.2 × 1.4–2.2 mm, apex abruptly cuspidate, involute; keel 4.5–4.8 mm, crest 2-parted, with 2 or 3 entire or 2-fid lobes on each side. Capsules subglobose, 1–1.5 × 1–1.5 mm, margins not winged. Seeds 0.6–0.9 mm, glabrous; aril minute (usually appearing vestigial, usually less than 0.05 mm), unlobed. 2n = 64, 68.

Flowering spring–summer. Wet depressions in savannas, pine flatwoods, bogs, edges of acidic swamps, cypress ponds, Carolina bays, marshes, emergent aquatics, especially in seasonally ponded Coastal Plain depressions; 0–100 m; Ala., Del., Fla., Ga., La., Miss., N.C., S.C.

Reports of Polygala cymosa from Maryland (M. L. Brown and R. G. Brown 1984, as cited in the USDA Plants database) and Texas (M. Pollard et al. 2009) are in error; no vouchers are known from Maryland and the specimen cited for Texas is P. ramosa.