Repert. Spec. Nov. Regni Veg. 40: 295. 1936.
Plants perennial, glabrous, with vertical rootstock. Stems procumbent, occasionally ascending, usually producing axillary shoots below 1st-order inflorescence or at proximal nodes, 20–50(–60) cm. Leaf blades ovate-lanceolate, elliptic-lanceolate, or ovate-elliptic, 3–12 × 1–5 cm, usually not more than 2–3.5 times as long as wide, widest near middle or occasionally in proximal 1/2, thick, coriaceous, base broadly cuneate, occasionally almost truncate or cuneate, margins entire, flat, apex acute. Inflorescences terminal and axillary, terminal usually occupying distal 1/3–1/2 of stem, dense or interrupted only near base, usually broadly paniculate (branches simple or nearly so). Pedicels articulated in proximal 1/3 or almost near base, usually rather thick, 4–9 mm, not more than 2–2.5 times as long as inner tepals, articulation distinctly swollen. Flowers 10–25 in whorls; inner tepals broadly ovate, ovate, or lingulate-deltoid, (3–)4–5 × (2.5–)3–4 mm, base rounded or subtruncate, margins entire or indistinctly erose, apex acute or subacute; tubercle 1, large, subequal to inner tepals, or slightly narrower than inner tepals (then free margins of inner tepal distinctly narrower than tubercle), subglabrous to verrucose. Achenes brown or dark reddish brown, 2–2.5 × 1.7–2.1 mm. 2n = 20.
Phenology: Flowering early spring–summer.
Habitat: Coastal dunes, sandy shores and marshes
Elevation: 0-100 m