Tiny or Small’s milkwort

Polygala arenicola Small, Bull. New York Bot. Gard. 3: 426. 1905, not Gürke 1903; Pilostaxis arenicola Small

Herbs biennial, usually single-stemmed, rarely multi-stemmed, 0.2–0.5(–0.8) dm, unbranched; from taproot or fibrous root cluster. Stems erect, glabrous. Leaves with persistent basal rosette, clustered and irregular, crowded; alternate; sessile or subsessile with narrowed petiolelike region to 5(–10) mm (usually obscured by tightly clustered leaves); blade oblanceolate to linear-oblanceolate, 10–42 × 2–14 mm, succulent, base cuneate, apex usually rounded to obtuse, rarely acute, sometimes apiculate, surfaces glabrous. Racemes capitate, 0.4–3 × 0.5–1.8 cm; peduncle 0.5–5 cm; bracts deciduous, often tardily so, linear-subulate. Pedicels winged, 0.4–0.8 mm, glabrous. Flowers green or greenish yellow, 4.5–6(–8) mm; sepals decurrent on pedicel, narrowly ovate to lanceolate, (2–)3–5 mm, sometimes ciliolate; wings usually lanceolate, sometimes oblong-lanceolate, 4–6(–8) × 1–2 mm, apex long-acuminate, sometimes slightly involute, tip 0.5–0.9 mm; keel (3.5–)4(–5.5) mm, crest 2-parted, with 3 2-fid or entire lobes on each side; stamens 6–8. Capsules broadly ellipsoid to subglobose, 1.6–2 × 1.2–1.6 mm, margins not winged. Seeds 1.9–2.3 mm, pubescent; aril 0.9–1.6 mm, lobes 1/2 to ± equal length of seed. 2n = 64, 68.

Flowering spring (year-round). Pinelands; of conservation concern; 0–50 m; Fla.

Polygala smallii is known from Broward, Martin, Miami-Dade, Palm Beach, and St. Lucie counties.

Compared to Polygala nana, the most similar species, P. smallii is smaller and more compact (stems and inflorescences are shorter and almost always surpassed by the tightly clustered leaves), leaves are narrower with a less conspicuously narrowed petiole­like portion (less obviously spatulate), wing sepals are more strongly lanceolate (tapering more to the apex, whereas P. nana wings typically are more elliptic or oblong-lanceolate), flowers are much greener at anthesis, and seeds are longer.

Polygala smallii is in the Center for Plant Conser­vation’s National Collection of Endangered Plants.