Ludwigia maritima

R. M. Harper

Torreya 4: 163, fig. 2. 1904.

Common names: Seaside primrose-willow
Treatment appears in FNA Volume 10.

Roots fibrous or fusiform, sometimes fascicled. Stems subterete to scarcely angled, with narrow raised lines or wings de­current from leaf axils, 30–90 cm, simple or sparsely branched distally, strigillose to some­times glabrate. Leaves: stipules nar­rowly deltate, 0.05–0.2 × 0.05–0.1 mm; sessile; blade ovate proxi­mally, lanceolate to lanceolate-linear distally, (2–)3–8 × 0.3–1.5 cm, base cuneate, margins entire, apex acute, surfaces glabrate to strigillose or hirsute; bracts usually much reduced, sublinear. Inflorescences sparse racemes, flowers solitary in leaf axils; bracteoles attached in subopposite pairs on distal 1/3 of pedicel, lanceolate-linear, 0.7–3.2(–5) × 0.2–0.5 mm, margins entire, apex acute, surfaces strigillose. Flowers: sepals often spreading, ovate-deltate, (4.5–)5.5–8(–9) × 3–5 mm, margins entire, apex acute to obtuse, sur­faces strigillose; petals cordate, 9–12 × 8–10 mm, base attenuate, apex emarginate; filaments yellow, awl-shaped, 1.9–3.2 mm, anthers 1.2–2.5 × 0.4–0.7 mm; ovary subcuboid or globose, 3–4.5 × 3–4 mm; nectary disc elevated, domed, 0.9–1.3 mm diam., prominently 4-lobed, ringed with sparse, spreading hairs; style 1.5–3.3 mm, glabrous, stigma capitate to hemi­spher­ical, 0.6–1.2 × 1.4–1.9 mm, shallowly 4-lobed, not exserted beyond anthers. Capsules subcuboid to squarish globose, 4–7 ×4–5 mm, 4-angled, often also 4-winged, wings 0.3–1.2 mm wide, pedicel 5–17 mm. Seeds light brown, oblong to reni­form, 0.4–0.6 ×0.2–0.4 mm, surface cells elongate trans­versely to seed length, except may be parallel to seed length near raphe. 2n = 16.

Phenology: Flowering summer.
Habitat: Damp, sandy, or peaty habitats, roadside ditches, margins of bogs or fields, usually within 75 miles of sea coast.
Elevation: 0–200 m.


Ala., Fla., Ga., La., Miss., N.C., S.C.


Selected References


Lower Taxa

... more about "Ludwigia maritima"
Peter C. Hoch +
R. M. Harper +
Seaside primrose-willow +
Ala. +, Fla. +, Ga. +, La. +, Miss. +, N.C. +  and S.C. +
0–200 m. +
Damp, sandy, or peaty habitats, roadside ditches, margins of bogs or fields, usually within 75 miles of sea coast. +
Flowering summer. +
Isnardia subg. Ludwigiaria +
Ludwigia maritima +
Ludwigia sect. Ludwigia +
species +