Elatine minima (Nutt.) Fisch. & C.A.Mey.

Herbs, submersed or emersed on wet substrates, 0.2–3(–10) cm. Stems erect or ascending, usually unbranched, sometimes 1–2 branched. Leaves green; stipules lanceolate, 0.2 mm, margins entire, apex rounded; petiole 0–1 mm; blade elliptic to oblanceolate or spatulate, 0.3–5(–11) × 0.7–1.8(–4) mm, base rounded to truncate, apex obtuse-acute. Pedicels 0–0.2 mm, erect. Flowers cleistogamous when submersed; sepals 2, equal, ovate to oblong, 0.5 × 0.3 mm; petals 2, reddish, long-elliptic, elliptic, or ovate, 1–1.5 × 0.5 mm; stamens 2; styles 2. Capsules oblong-ovoid, 2-locular, 0.9–1.5 mm diam. Seeds 4–9 per locule, thickly cylindric to barrel-shaped, straight, 0.4–0.5(–0.7) × 0.2(–0.3) mm; pits elliptic, length 1.2–1.6 times width, in 8–9 rows, (11–)15–20 per row.