Ludwigia suffruticosa


Fl. Carol., 90. 1788.

Common names: Shrubby primrose-willow or seedbox
Synonyms: Isnardia suffruticosa (Walter) Kuntze
Treatment appears in FNA Volume 10.

Herbs with 1–3 rhizomes 0.6–5.5 × 0.2–0.5 mm, often branched, glabrous or densely hirtellous, sometimes also form­ing stolons 8–80 cm, 1.1–2.2 mm thick, branched, glabrous or sparsely to densely hirtellous. Stems erect, slightly ridged, unbranched or slightly branched, (16–)30–90 cm, glabrous or strigillose to hirtellous, especially on distal parts. Leaves alternate; stipules deltate, 0.25–0.45 × 0.15–0.4 mm; rhizomes: sessile, blades minute, appressed, and scalelike, oblate or suborbiculate, 0.3–0.6 × 0.6–0.9 mm; stolons: petiole 0.1–0.6 cm, blade oblong or oblanceolate-elliptic to spatulate, 0.4–3.5 × 0.2–1.5 cm; main stem: sessile, blade lanceolate-elliptic or lanceolate-linear to linear, 2.5–9.5 × (0.1–)0.3–0.9 cm, proximal ones shorter and often oblong or oblong-lanceolate, base rounded or obtuse, margins entire with obscure hydathodal glands, apex acuminate to acute, surfaces glabrous or, sometimes, pilose on proximal blades; bracts very reduced. Inflorescences densely clustered, terminal racemes or spikes, 1–5(–12) cm; bracteoles attached at base of ovary or on pedicel distally, narrowly lanceolate, 3.5–5(–6) × (1.2–)1.4–2 mm, surfaces usually glabrous, sometimes pilose abaxially. Flowers: sepals ascending, pale green or white adaxially, broadly ovate-deltate, 2.3–3.5(–4) × 2.3–3.2(–3.8) mm, margins entire, apex acuminate, surfaces glabrous; petals 0; filaments yellow or cream, 1.2–2 mm, distinctly dilated toward base, anthers 0.7–1(–1.3) × 0.5–0.7 mm; pollen shed in tetrads; ovary broadly obovoid or cup-shaped, 2.2–3 × 2.3–3.3 mm; nectary disc elevated 0.5–0.6 mm on ovary apex, pale yellow, 1.8–3.1 mm diam., obscurely 4-lobed, glabrous; style pale yellow, 0.9–1.7 mm, gla­brous, stigma pale green to white, globose to capi­tate, 0.4–0.8 × 0.5–0.8 mm, distinctly 4-lobed, not exserted beyond anthers. Capsules broadly obpyramidal, angles rounded, sometimes subspherical, 2.5–4.3 ×2.5–4.5(–5) mm, hard-walled, dehiscent by apical ring, pedicel 0.5–1.5(–2) mm. Seeds brown, elliptic-oblong, curved on both ends, 0.5–0.6 × 0.2–0.3 mm, surface cells ± isodiametric. 2n = 32.

Phenology: Flowering May–Sep.
Habitat: Sandy ditches, marshes, wet meadows, limestone sinks, cypress swamps, moist pinelands.
Elevation: 0–150 m.


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


Ludwigia suffruticosa is distinctive by virtue of its highly condensed inflorescence and sessile leaves. It also differs from other species in sect. Isnardia in that it perennates mainly by underground rhizomes. This apetalous species has showy bracts and attracts many insects, including bumblebees, wasps, and honeybees (C. I. Peng 1989). Its center of distribution is in Florida, extending along the coastal plain barely to Alabama on the west and barely to southern North Carolina on the northeast. Recent reports of this species from Mississ­ippi and from Mexico (Chiapas and Oaxaca) have not been confirmed.

Selected References


Lower Taxa

... more about "Ludwigia suffruticosa"
Peter C. Hoch +
Walter +
Isnardia +
Shrubby primrose-willow or seedbox +
Ala. +, Fla. +, Ga. +, N.C. +  and S.C. +
0–150 m. +
Sandy ditches, marshes, wet meadows, limestone sinks, cypress swamps, moist pinelands. +
Flowering May–Sep. +
Fl. Carol., +
Isnardia suffruticosa +
Ludwigia suffruticosa +
Ludwigia sect. Isnardia +
species +