Ludwigia palustris |
Ludwigia brevipes |
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common water-primrose, eastern false loosestrife, ludwigie palustre, marsh primrose-willow, marsh purslane, marsh seedbox, water-purslane |
Long Beach primrose-willow, ludwigiantha brevipes |
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Habit | Herbs often creeping, rooting at nodes, forming mats. | Herbs creeping and rooting at nodes, sometimes forming large mats. |
Stems | prostrate or decumbent and ascending at tips, subterete or with raised lines decurrent from leaf axils, well branched, 10–50(–70) cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
prostrate, ascending or erect at tips, terete, well branched, 20–70 cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
Leaves | opposite; stipules narrowly deltate, 0.05–0.1 × 0.05–0.1 mm; petiole narrowly winged, 0.1–2.5 cm, blade narrowly to broadly elliptic or ovate-elliptic, 0.5–4.5 × 0.3–2.3 cm, base abruptly attenuate, margins entire and minutely strigillose, apex subacute, surfaces glabrous; bracts not reduced. |
opposite; stipules narrowly deltate, 0.05–0.15 × 0.05–0.1 mm; petiole narrowly winged, 0.2–0.8 cm, blades on submerged stems linear, 3.2–4.7 × 0.2–0.3 cm, those on emergent ones oblanceolate-elliptic to narrowly oblanceolate, (0.7–)1–1.7(–2) × 0.2–0.7(–1.1) cm, base very narrowly cuneate or attenuate, margins entire, apex acute; bracts not reduced. |
Inflorescences | leafy spikes or racemes, flowers usually paired in leaf axils of prostrate stems; bracteoles attached at base or to 2.5 mm distal to base of ovary, sublinear, 0.3–1(–1.8) × 0.1–0.8 mm. |
sometimes few-flowered, erect racemes, flowers paired in leaf axils of prostrate stems; bracteoles attached in opposite pairs at base of ovary or on pedicel distally, linear, 1–3(–4.5) × 0.1–0.7 mm, apex acuminate. |
Flowers | sepals ascending, green, ovate-deltate, 1.1–2 × 1–2.1 mm, margins finely serrulate with minute hairs, apex acuminate, sometimes with blunt tip, surfaces glabrous; petals 0; filaments translucent, 0.4–0.6 mm, anthers 0.2–0.4 × 0.3–0.6 mm; pollen shed singly; ovary oblong, 1.5–3.5 × 1–2 mm, glabrate; nectary disc elevated 0.15–0.3 mm on ovary apex, green, 1–2 mm diam., 4-lobed, glabrous; style pale green, 0.3–0.7 mm, glabrous, stigma subglobose or capitate, 0.4–0.6 × 0.2–0.4 mm, not exserted beyond anthers. |
sepals slightly reflexed at anthesis, ascending in fruit, light green, ovate-deltate or narrowly so, (3.5–)4–5(–6) × 1.7–3 mm, with 3 parallel veins, margins strigillose and finely serrulate, apex narrowly acute to elongate-acuminate, surfaces glabrous; petals sometimes caducous, oblong-spatulate, 4.5–5.5 × 1.5–3 mm, base attenuate, apex obtuse; filaments spreading, pale cream, 1.8–2.5 mm, anthers 0.7–1 × 0.5–0.7 mm; pollen shed in very loose tetrads; ovary obconic-cylindric, subterete or scarcely 4-angled, 3–5 × 2–2.5 mm; nectary disc elevated 0.5–0.7 mm on ovary apex, bright yellow, 1.7–2.3 mm diam., 4-lobed, glabrate; style cream, 1.1–1.7 mm, stigma cream, broadly capitate, 0.4–0.6 × 0.5–0.8 mm, often exserted beyond spreading stamens. |
Capsules | oblong obovoid, 4-angled, (1.6–)2–5 × 1.5–3(–3.5) mm, thin-walled, irregularly dehiscent or dispersing as unit, pedicel 0–0.5 mm. |
clavate, subterete to obscurely 4-angled, sometimes slightly curved, 6–10.5 × 2.5–4 mm, hard-walled, irregularly dehiscent, pedicel (4.5–)6–15(–20) mm. |
Seeds | yellowish brown, ellipsoid, 0.5–0.7 × 0.3–0.4 mm, surface cells transversely elongate. |
light to dark brown, ellipsoid, 0.6–0.7 × 0.3–0.5 mm, surface cells transversely elongate. |
2n | = 16. |
= 48. |
Ludwigia palustris |
Ludwigia brevipes |
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Phenology | Flowering Feb–Oct. | Flowering Jun–Sep. |
Habitat | Roadside ditches, wet meadows, dried pond bottoms, margins of ponds, swamps, rivers, alluvial sand bars. | Wet soil or sand along edges of ponds, lakes, marshes, or rivers, moist dune hollows, seasonal ponds. |
Elevation | 0–1000[–2700] m. (0–3300[–8900] ft.) | 0–200 m. (0–700 ft.) |
Distribution |
AL; AR; AZ; CA; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; BC; NB; NF; NS; ON; QC; Mexico (Chiapas, Chihuahua, Guerrero, Hidalgo, Jalisco, México, Michoacán, Morelos, Nuevo León, Oaxaca, San Luis Potosí, Sinaloa, Sonora, Tamaulipas, Veracruz); West Indies (Cuba, Hispaniola, Jamaica, Puerto Rico); Bermuda; Central America (Costa Rica, Guatemala, Panama); South America (Colombia, Peru, Venezuela); Europe; sw Asia; Africa; introduced in Pacific Islands (Hawaii, New Zealand); Australia
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FL; NC; NJ; SC; VA
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Discussion | Ludwigia palustris is a common diploid and most widely distributed species in sect. Isnardia. It is particularly widespread in temperate North America and in Europe [the type is thought to be from Europe (P. H. Raven 1963[1964]; C. I. Peng et al. 2005)], more sporadically in Africa and sw Asia, and introduced in Australasia, and Hawaii. The close sister relationship of sect. Isnardia with sect. Miquelia (L. ovalis Miquel only, endemic to eastern Asia) suggests that this clade may have had a history connected with the evolution of the Arcto-Tertiary Geoflora (P. H. Raven and D. I. Axelrod 1974; Peng et al.). Ludwigia palustris is known to hybridize with L. brevipes producing the sterile L. ×lacustris Eames. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The hexaploid Ludwigia brevipes is mainly restricted to the Atlantic coastal plain from central and eastern South Carolina to eastern North Carolina and extreme southeastern Virginia. The type collection of L. brevipes from middle New Jersey remains the only disjunct population north of the main range of this species more than 100 years after it was found. In 1988, an isolated population was found in the panhandle of Florida (Escambia County, Burkhalter 11065, MO) far to the southwest of the main range of L. brevipes; other reports of the species from Florida were erroneous (C. I. Peng 1989). Ludwigia brevipes is known to hybridize with L. palustris producing the sterile L. ×lacustris Eames. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia |
Sibling taxa | ||
Synonyms | Isnardia palustris, I. ascendens, I. nitida, I. palustris var. americana, L. apetala, L. nitida, L. palustris var. americana, L. palustris var. inundata, L. palustris var. liebmannii, L. palustris var. nana, L. palustris var. pacifica | Ludwigiantha brevipes |
Name authority | (Linnaeus) Elliott: Sketch Bot. S. Carolina 1: 211. (1817) | (Long) Eames: Rhodora 35: 228. (1933) — (as Ludvigia) |
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