Baldwin's nailwort

Anychia baldwinii Torrey & A. Gray, Fl. N. Amer. 1: 172. 1838; Anychiasatrum baldwinii (Torrey & A. Gray) Small; A. riparium (Chapman) Small; Paronychia baldwinii var. ciliata Chaudhri; P. baldwinii subsp. riparia (Chapman) Chaudhri; P. riparia Chapman

Plants annual, biennial, or perennial, often matted; taproot slender. Stems prostrate to erect, branched, 5-70 cm, mostly retrorsely to spreading-pubescent on 1 side or throughout. Leaves: stipules lanceolate, 2-6 mm, apex acuminate, entire; blade oblong to elliptic or oblanceolate, 3-25 × 1-6 mm, herbaceous, apex acute and briefly cuspidate, glabrous. Cymes terminal, 20-40+-flowered, diffuse, lax, repeatedly forked or dichotomous. Flowers 5-merous, ± short-cylindric, with enlarged hypanthium and calyx cylindric, 1-1.7 mm, glabrous to pubescent with short hairs, often minutely ciliate, sometimes glaucous; sepals greenish or greenish white to brownish, veins absent, ovate to oblong, 0.8-1.3 mm, herbaceous, margins white, 0.05-0.1 mm wide, scarious to papery, apex terminated by minute cusp, hood narrowly rounded, cusp light green to whitish, straight, short-conic, 0.1-0.15 mm, minutely scabrous; staminodes subulate, 0.2-0.3 mm; style 1, cleft in distal 4/ 5+, 0.2-0.4 mm. Utricles ellipsoid, 1-1.3 mm, papillate distally.

Flowering summer-fall. Dunes, woodlands, fields, clearings, roadsides, riverbanks, hummocks, waste places; 0-200 m; Ala., Fla., Ga., N.C., S.C., Va.

Chaudhri used duration and pubescence to recognize two subspecies of Paronychia baldwinii, characters that L. H. Shinners (1962c) found to vary independently in this species.