Herbs slender, usually with aerenchyma near base, forming stolons 10–30 cm, 0.8–2.5 mm thick. Stems erect, slightly ridged, often well branched, (22–)50–100(–145) cm, glabrous or sparsely to densely, minutely strigillose. Leaves alternate; stipules narrowly ovate or lanceolate, 0.15–0.3 × 0.05–0.15 mm; stolons: petiole attenuate, 0.2–0.5 cm, blade narrowly to very narrowly elliptic, 1–2.5 × 0.3–0.9 cm, surfaces glabrous or minutely strigillose; stems: subsessile, blade linear to elliptic-linear, 1.6–6(–8.5) × 0.1–0.4(–0.6) cm, base very narrowly cuneate, margins entire with obscure hydathodal glands, apex very narrowly acute, surfaces glabrous or sparsely to densely, minutely strigillose or puberulent; bracts not much reduced. Inflorescences leafy racemes or spikes, flowers solitary in leaf axils; bracteoles deciduous, attached on pedicel near ovary base or to 4.5 mm distal to base, linear, 0.4–4(–7.5) × 0.1–0.3 mm. Flowers: sepals ascending, green, lanceolate-deltate to narrowly so, 2.5–5(–5.5) × 1–3(–3.5) mm, margins entire, apex acuminate or elongate-acuminate to cuspidate, surfaces sparsely to densely strigillose; petals obovate to suborbiculate, 3–6 × (2–)2.5–5 mm, base attenuate, margins entire, apex obtuse; filaments white or cream, 1.1–2.2 mm, anthers lanceolate-oblong, 1–2 × 0.6–1 mm; pollen shed in tetrads; ovary cylindric (wider at apex), 2.5–4.5 ×1–2.5 mm, strigillose; nectary disc elevated (0.2–)0.3–0.6 mm on ovary apex, yellow, 1.3–2.5 mm diam., 4-lobed, margins glabrous or minutely strigillose; style yellowish green, (0.4–)0.7–1.5 mm, glabrous or densely strigillose on proximal part, stigma clavate to subcapitate, (0.6–)1–1.9 × 0.6–0.9 mm, shallowly 4-lobed, not exserted beyond anthers. Capsules elongate-obpyramidal, obscurely 4-angled, often with central, longitudinal groove on each side, 5–10(–12) × 2–5.5 mm, hard-walled, dehiscent by apical ring, ped­icel 0–3.5(–5) mm. Seeds light brown, oblong-elliptic,0.5–0.7 × 0.2–0.3 mm, surface cells oblong, elongate either parallel or transversely to seed length. 2n = 16.

Phenology: Flowering late Jun–Sep.
Habitat: Drainage ditches, along river or stream banks, swales, edges of pocosins, sandy soil in wet meadows, brackish marshes, disturbed ground.
Elevation: 0–300 m.

Distribution

• Generated Map
• Legacy Map

Ala., Ark., Del., Fla., Ga., La., Md., Miss., Mo., N.J., N.C., Okla., S.C., Tenn., Tex., Va.

Discussion

Ludwigia linearis is widespread in the southeastern United States, with a complex pattern of morphological variation, especially in stem pubescence, ranging from glabrous to densely strigillose, but without strong geographical separation (C. I. Peng 1989).

Selected References

None.

Lower Taxa

None.