Ludwigia peploides |
Ludwigia linearis |
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creeping water primrose, floating primrose-willow, marsh purslane |
narrowleaf primrose-willow |
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Habit | Herbs or emergent aquatics, rooting at nodes, sometimes with fleshy, white pneumatophores at submerged nodes. | Herbs slender, usually with aerenchyma near base, forming stolons 10–30 cm, 0.8–2.5 mm thick. | ||||||||
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, slightly ridged, often well branched, (22–)50–100(–145) cm, glabrous or sparsely to densely, minutely strigillose. |
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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 narrowly ovate or lanceolate, 0.15–0.3 × 0.05–0.15 mm; stolons: petiole attenuate, 0.2–0.5 cm, blade narrowly to very narrowly elliptic, 1–2.5 × 0.3–0.9 cm, surfaces glabrous or minutely strigillose; stems: subsessile, blade linear to elliptic-linear, 1.6–6(–8.5) × 0.1–0.4(–0.6) cm, base very narrowly cuneate, margins entire with obscure hydathodal glands, apex very narrowly acute, surfaces glabrous or sparsely to densely, minutely strigillose or puberulent; 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. |
leafy racemes or spikes, flowers solitary in leaf axils; bracteoles deciduous, attached on pedicel near ovary base or to 4.5 mm distal to base, linear, 0.4–4(–7.5) × 0.1–0.3 mm. |
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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, green, lanceolate-deltate to narrowly so, 2.5–5(–5.5) × 1–3(–3.5) mm, margins entire, apex acuminate or elongate-acuminate to cuspidate, surfaces sparsely to densely strigillose; petals obovate to suborbiculate, 3–6 × (2–)2.5–5 mm, base attenuate, margins entire, apex obtuse; filaments white or cream, 1.1–2.2 mm, anthers lanceolate-oblong, 1–2 × 0.6–1 mm; pollen shed in tetrads; ovary cylindric (wider at apex), 2.5–4.5 ×1–2.5 mm, strigillose; nectary disc elevated (0.2–)0.3–0.6 mm on ovary apex, yellow, 1.3–2.5 mm diam., 4-lobed, margins glabrous or minutely strigillose; style yellowish green, (0.4–)0.7–1.5 mm, glabrous or densely strigillose on proximal part, stigma clavate to subcapitate, (0.6–)1–1.9 × 0.6–0.9 mm, shallowly 4-lobed, 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, obscurely 4-angled, often with central, longitudinal groove on each side, 5–10(–12) × 2–5.5 mm, hard-walled, dehiscent by apical ring, pedicel 0–3.5(–5) mm. |
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Seeds | embedded in elongated piece of endocarp, 1–1.5 × 0.9–1.3 mm. |
light brown, oblong-elliptic,0.5–0.7 × 0.2–0.3 mm, surface cells oblong, elongate either parallel or transversely to seed length. |
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2n | = 16. |
= 16. |
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Ludwigia peploides |
Ludwigia linearis |
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Phenology | Flowering late Jun–Sep. | |||||||||
Habitat | Drainage ditches, along river or stream banks, swales, edges of pocosins, sandy soil in wet meadows, brackish marshes, disturbed ground. | |||||||||
Elevation | 0–300 m. (0–1000 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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AL; AR; DE; FL; GA; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
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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 linearis is widespread in the southeastern United States, with a complex pattern of morphological variation, especially in stem pubescence, ranging from glabrous to densely strigillose, but without strong geographical separation (C. I. Peng 1989). (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 linearis, L. angustifolia, L. linearis var. puberula | ||||||||
Name authority | (Kunth) P. H. Raven: Reinwardtia 6: 393. (1964) | Walter: Fl. Carol., 89. (1788) | ||||||||
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