Ludwigia peploides |
Ludwigia repens |
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creeping water primrose, floating primrose-willow, marsh purslane |
creeping primrose-willow, creeping water primrose, creeping waterpurslane, red ludwigia |
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Habit | Herbs or emergent aquatics, rooting at nodes, sometimes with fleshy, white pneumatophores at submerged nodes. | Herbs creeping and rooting at nodes, often forming loose mats. | ||||||||
Stems | floating or creeping and ascending to erect, terete, 10–100(–300) cm, simple or branched, glabrous or sparsely to densely villous, hairs sometimes viscid on emergent distal stem. |
prostrate, ascending to suberect at tips, terete, sparsely branched, 30–80 cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
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Leaves | stipules broadly ovate-deltate, 0.6–1.6 × 0.4–1 mm, succulent, apex acute or obtuse, gland-tipped, rarely divided into 3 parts; petiole flattened or narrowly winged, 0.2–6 cm; blade narrowly oblong or elliptic to ovate, broadly obovate, or orbiculate, (0.4–)1–10 × 0.4–4 cm, base narrowly cuneate or attenuate, margins entire, apex obtuse or rounded to acute, sometimes mucronate or glandular-mucronate, surfaces of floating leaves glabrous, those of emergent leaves glabrous to sparsely or densely strigillose at least adaxially; bracts scarcely reduced. |
opposite; stipules narrowly deltate, 0.05–0.1 × 0.05–0.1 mm; petiole narrowly winged, 0.3–2.3 cm, blade narrowly elliptic to broadly lanceolate-elliptic or suborbiculate, 0.8–4.5 × 0.4–2.7 cm, base attenuate, margins entire or sometimes with hydathodal glands, apex acute or apiculate, rarely obtuse, surfaces lustrous, subglabrous or sparingly to densely papillose strigillose; bracts not much reduced. |
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Inflorescences | on emergent stems sometimes in leafy racemes, flowers solitary in leaf axils; bracteoles (rarely absent), deltate, squamate, 0.5–1 × 0.5–1 mm, apex acute, attached near base or on lower 1/2 of ovary. |
sometimes few-flowered, erect racemes, flowers paired in leaf axils of prostrate stems; bracteoles attached in opposite pairs to pedicel 1–5 mm proximal to base of ovary, lanceolate to narrowly oblong-lanceolate or sublinear, 1–5(–8) × 0.2–1 mm, apex acute, surfaces sparingly minutely strigillose. |
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Flowers | sepals narrowly deltate or lanceolate, 3–12 × 1.5–4 mm, apex acute or acuminate, surfaces glabrous or sparsely to densely hirtellous; petals yellow, obpyramidal,7–24 × 4–13 mm, apex mucronate or emarginate, up-curved; stamens 10(or 12), in 2 unequal series, bright yellow, filaments suberect or reflexed, shorter ones 1.4–4.2 mm, longer ones (1.9–)3.3–6 mm, anthers oblong, 0.5–2.2 mm; ovary subcylindric or truncate, 6–20 × 1.5–3 mm, apex somewhat broader, glabrous or sparsely to densely hirtellous; nectary disc slightly raised on ovary apex, 2–2.5 mm diam., lobed, glabrous or fringed with long hairs; style (1.9–)2.4–7.3 mm, glabrous or sparsely to densely hirtellous on proximal 1/2, stigma flattened-globose, 0.9–1.2 × 1–2.5 mm, sometimes shallowly or deeply 5-lobed, as long as or exserted beyond anthers. |
sepals ascending, light green, ovate deltate to narrowly so, 1.8–5 × 1.5–3.5 mm, margins minutely strigillose, apex acuminate to elongate-acuminate, surfaces subglabrous; petals caducous, oblanceolate to elliptic-oblong, 1.1–3 × 0.4–1.4 mm, base attenuate, apex obtuse, often variable in size and shape in same flower; filaments pale yellow, 0.5–1.5 mm, slightly inflated near base, anthers 0.4–0.9 × 0.3–0.8 mm; pollen shed singly or in tetrads; ovary obconic-cylindric, barely 4-angled to subterete, 2–6 × 2.5–3.5 mm; nectary disc elevated 0.3–0.8 mm on ovary apex, yellow, 1.1–3 mm diam., 4-lobed, glabrous; style pale yellow, 0.6–0.9 mm, glabrous, stigma pale yellow, broadly capitate, 0.3–0.5 × 0.3–0.8 mm, usually not exserted beyond anthers. |
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Capsules | cylindric, subterete to obscurely 5-angled, straight or curved, 10–40 × 2–4 mm, with thick woody walls, irregularly and tardily dehiscent, pedicel 7–60(–90) mm. |
elongate-obpyramidal, 4-angled, corners sometimes rounded, 4–10 × 2.5–4 mm, hard-walled, irregularly dehiscent, pedicel 0.1–3 mm. |
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Seeds | embedded in elongated piece of endocarp, 1–1.5 × 0.9–1.3 mm. |
yellowish brown, ellipsoid, 0.6–0.8 × 0.3–0.5 mm, surface cells transversely elongate. |
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2n | = 16. |
= 48. |
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Ludwigia peploides |
Ludwigia repens |
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Distribution |
United States; Mexico; Central America; South America; West Indies (Cuba); Asia (China); Pacific Islands (Galapagos Islands) [Introduced in Europe (France), elsewhere in the Pacific Islands (New Zealand, Society Islands), Australia]
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Discussion | Subspecies 4 (3 in the flora). Ludwigia peploides consists of four subspecies more or less well defined geographically and morphologically, with three present in the flora area: subsp. glabrescens, subsp. montevidensis, and subsp. peploides (P. H. Raven 1963[1964]); these subspecies have ranges that are mostly distinct. Subspecies peploides has a wide distribution in the New World, from the southern United States south to Argentina. Subspecies glabrescens is widespread in eastern United States. Subspecies montevidensis occurs primarily in southern South America and scattered (probably introduced) in the southern United States, Australia, France, and New Zealand. Subspecies peploides and montevidensis occur together locally in California and Louisiana, where subsp. montevidensis is introduced. The ranges of subsp. glabrescens and peploides come together in Texas. Subspecies stipulacea (Ohwi) P. H. Raven is known from eastern Asia (e China). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Flowers Mar–Nov (year-round). Muddy or damp, sandy edges of pools, lakes, swamps, creeks, and roadside ditches, moist soil in solution pits in limerock and hammock clearings in Florida Everglades, shade or sun; 0–1200[–1600] m; Ala., Ariz., Calif., Fla., Ga., Kans., La., Miss., Nev., N.J., N.Mex., N.C., Okla., Oreg., S.C., Tenn., Tex., Va.; Mexico (Chihuahua, Coahuila, México, Morelos, Nuevo León, Puebla, San Luis Potosí, Sonora); West Indies (Bahamas, Cuba, Hispaniola, Jamaica); Bermuda; introduced in Asia (Bangladesh, Japan). Ludwigia repens occurs primarily on the Atlantic and Gulf coastal plains of the United States from North Carolina to Texas, with more scattered distribution into west Texas, New Mexico, Oklahoma, and Kansas, and disjunct populations in New Jersey, Tennessee, southern Arizona, Nevada, California, and western Oregon (Marion County); it also occurs in northern and central Mexico and the Caribbean region. In some parts of this wide range it is considered an aquatic weed. Ludwigia repens is one of the most popular species of Ludwigia used in the aquarium trade; this may help to account for its wide distribution. Much like the related diploid Ludwigia palustris, the hexaploid L. repens is widespread and morphologically variable, and infraspecific taxa have been proposed to describe this variation. Given the tendency of species in sect. Isnardia to hybridize, and the lack of a geographical basis for much of the variation, C. I. Peng (1989) declined to adopt any infraspecific classification, and this treatment follows Peng. As described in C. I. Peng et al. (2005), Ludwigia repens J. R. Forster was conserved with a new type (the original type selected was from Virginia, where the species does not occur); L. repens Swartz (1797) was a later homonym described from Jamaica and pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 10. | FNA vol. 10. | ||||||||
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Jussiaea | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Jussiaea peploides, J. repens var. peploides, L. adscendens var. peploides | Isnardia intermedia, I. natans, I. repens, I. repens var. rotundata, L. fluitans, L. natans, L. natans var. rotundata, L. natans var. stipitata, L. repens var. rotundata, L. repens var. stipitata | ||||||||
Name authority | (Kunth) P. H. Raven: Reinwardtia 6: 393. (1964) | J. R. Forster: Fl. Amer. Sept., 6. (1771) — (as Ludvigia), name conserved | ||||||||
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