Ludwigia curtissii

Herbs rarely creeping and rooting at nodes, stolons usu­ally absent. Stems erect or ascending at base, very rarely prostrate, unbranched to well branched, branches sometimes very slender, 15–75 cm, gla­brous, with slightly raised lines decurrent from leaf axils. Leaves alternate; stipules reddish purple, narrowly ovate, 0.2–0.3 × 0.1–0.3 mm, succulent; petiole winged, 0.3–1.2 cm, blade usually oblanceolate-spatulate to spatulate or oblanceolate, rarely sublinear, 1–2.5(–3) × 0.1–0.8 cm, base attenuate, margins subentire with hydathodal glands, apex acute or mucronate, surfaces glabrous; bracts not reduced. Inflorescences usually not congested, leafy racemes or spikes, flowers solitary in leaf axils; bracteoles attached in opposite pairs near base of ovary, narrowly lanceolate, lanceolate-elliptic, or oblong-linear, 1.5–3.5(–4) × 0.4–0.8 mm, swollen at base, apex acuminate. Flowers: sepals ascending, green fading to white near base, ovate-deltate, 1.5–3 × 1.2–2 mm, margins entire, apex narrowly acute or acuminate, surfaces glabrous; petals 0(–3), narrowly elliptic or spatulate, 1–2.5 × 0.5–1 mm, base attenuate, apex obtuse; filaments pale yellow, 0.8–1(–1.3) mm, anthers 0.3–0.6 × 0.3–0.5 mm; pollen shed singly; ovary obovate-obpyramidal, 2–2.5 × 1.8–2.3 mm, glabrous; nectary disc elevated 0.3–0.4 mm on ovary apex, green, 0.9–1.6 mm diam., prominently 4-lobed, glabrous; style pale green, 0.4–0.7 mm, glabrous, stigma pale yellow, subglobose, 0.3–0.4 × 0.2–0.4 mm, not exserted beyond anthers. Capsules obconic, obscurely 4-angled, (2–)2.5–4(–4.7) × 2–3(–3.5) mm, hard-walled, dehiscent by loculicidal slits, pedicel 0.1–0.5 mm. Seeds light brown, ellipsoid, 0.4–0.6 × 0.3–0.4 mm, surface cells transversely elongate, glabrous or, sometimes, with surface wax that mimics appressed hairs. 2n = 64.

Phenology: Flowering Mar–Nov (year-round).
Habitat: Pine savannas and flatwoods, marshes, edges of ponds and streams, sandy or peaty swales, limestone prairies, solution pits on limestone.
Elevation: 0–50 m.

Distribution

• Generated Map
• Legacy Map

Fla., West Indies (Bahamas).

Discussion

Ludwigia curtissii is the only octoploid (n = 32) in sect. Isnardia, and is restricted to peninsular Florida and the Bahamas. It and L. simpsonii they are the only members of the section that do not form true stolons; instead they simply sprout new shoots from the base. The two species are similar in many ways and appear to share three genomes (C. I. Peng 1988).

Selected References

None.

Lower Taxa

None.