Ludwigia peploides |
Ludwigia lanceolata |
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creeping water primrose, floating primrose-willow, marsh purslane |
lanceleaf primrose-willow |
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Habit | Herbs or emergent aquatics, rooting at nodes, sometimes with fleshy, white pneumatophores at submerged nodes. | Herbs slender, with well-developed aerenchyma when base submerged, often forming stolons 10–40 cm, 2–3 mm thick, stolons with widely spaced leaves. | ||||||||
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. |
erect, subterete or slightly ridged, well branched distally, 45–100 cm, glabrous, with raisedlines decurrent from leaf axils. |
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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. |
alternate; stipules ovate to very broadly ovate, 0.2–0.5 ×0.1–0.3 mm, succulent; stolons: petiole winged, 0.2–1 cm, blade orbiculate or elliptic to broadly elliptic, 0.5–2.7 × 0.6–1.2 cm, base attenuate, apex rounded to acute; main stem: petiole winged, 0.1–0.5 cm, blade elliptic, oblanceolate, or narrowly oblanceolate to sublinear, 2–7.5 × 0.2–0.8(–1.4) cm, base narrowly cuneate, sometimes attenuate, margins entire with minute hydathodal glands, apex acute to narrowly acute, leaves on side branches much reduced; bracts sublinear, moderately 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. |
open spikes, flowers solitary in distal leaf axils; bracteoles attached in opposite pairs at or slightly distal to base of ovary, ovate-elliptic to very narrowly elliptic, 1.5–4.3 × 0.4–1.4 mm, often with a swollen base, margins minutely papillose, apex subacute. |
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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, pale green, broadly ovate-deltate, 1.5–2.5 × 1.8–3.3 mm, margins minutely papillose, apex usually acute, rarely acuminate, surfaces glabrous; petals 0; filaments nearly translucent, 1–1.4 mm, base dilated, anthers 0.4–0.6(–0.8) × 0.5–0.6 mm; pollen shed in tetrads; ovary broadly obovoid or cup-shaped, 2.5–3.5 × 2.2–3.2 mm; nectary disc elevated 0.4–0.6 mm on ovary apex, yellowish green, 1.8–2.6 mm diam., 4-lobed, glabrous; style yellowish green, 0.5–0.7 mm, glabrous, stigma yellowish green, broadly capitate to subglobose, 0.3–0.5 × 0.7–1 mm, 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. |
obpyramidal, sharply 4-angled and 4-winged, wings 0.3–0.7mm wide, 3.5–5 × 2.5–4.5 mm, hard-walled, dehiscent by apical ring, pedicel 0.1–0.5 mm. |
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Seeds | embedded in elongated piece of endocarp, 1–1.5 × 0.9–1.3 mm. |
light brown, narrowly oblong with constricted ends, 0.6–0.8 ×0.2–0.3 mm, surface cells nearly isodiametric. |
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2n | = 16. |
= 32. |
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Ludwigia peploides |
Ludwigia lanceolata |
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Phenology | Flowering Jun–Oct. | |||||||||
Habitat | Ditches, low meadows, cypress swamps, moist pinelands, edges of pocosins, sandy peaty soil. | |||||||||
Elevation | 0–100 m. (0–300 ft.) | |||||||||
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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FL; GA; NC; SC
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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.) |
Ludwigia lanceolata is fairly uncommon, with scattered populations occurring along the Atlantic coast of southern North Carolina, South Carolina, eastern and southern Georgia, and peninsular Florida. It reaches its western limit in the central panhandle of Florida. C. I. Peng (1988, 1989) found this tetraploid species to be interfertile with other tetraploid species in the section, but few natural hybrids are found, perhaps due to persistent autogamy and habitat specialization. (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 lanceolata | ||||||||
Name authority | (Kunth) P. H. Raven: Reinwardtia 6: 393. (1964) | Elliott: Sketch Bot. S. Carolina 1: 213. (1817) | ||||||||
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