Ludwigia leptocarpa |
Ludwigia decurrens |
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anglestem primrose-willow, anglestem waterprimrose |
wingleaf primrose-willow |
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Habit | Herbs, perennial or (robust) annual, or shrubs, often with woody base, when aquatic, forming white pneumatophores from nodes. | Herbs annual or short-lived perennial, roots and lower stem sometimes inflated and spongy. |
Stems | usually erect or strongly ascending, rarely floating or creeping, terete to somewhat angled on young branches, 30–250 cm, well branched to sparsely branched or simple, usually villous, often also strigillose, rarely glabrous, with raised lines decurrent from leaf axils. |
erect or strongly ascending, sharply 4-angled and 4-winged, 30–200 cm, simple to densely branched, glabrous. |
Leaves | stipules narrowly deltate, 0.1–0.2 × 0.1–0.2 mm; petiole 0.2–3.5 cm; blade broadly lanceolate, 3.5–18 × 1–4 cm, base narrowly cuneate, margins subentire, apex acuminate, surfaces hirsute or villous; bracts slightly to much reduced. |
stipules deltate, 0.4–0.5 × 0.2 mm; sessile and continuous with wings on stem; blade lanceolate or narrowly lanceolate to narrowly ovate or elliptic, 2–20 × 0.2–5 cm, base acute or rounded, margins entire, often minutely scabrid, apex acute or acuminate, membranous, surfaces glabrous or sometimes minutely puberulent on abaxial veins; bracts linear, mostly reduced. |
Inflorescences | leafy racemes, flowers solitary in axils; bracteoles often absent, when present, narrowly deltate, 2–3 × 1.2–2.4 mm, attached near ovary base. |
open, leafy racemes, flowers solitary in distal axils; bracteoles deciduous, usually attached near base of ovary, without subtending glands, lanceolate to subovate, 0.5–1 × 0.2–0.5 mm, apex acute. |
Flowers | sepals ovate-deltate, 5.5–11 × 1.5–3 mm, margins entire, apex acuminate, surfaces villous; petals orange-yellow, obovate, 5–11 × 4–8 mm; stamens (8 or)10 or 12(or 14), in 2 unequal series, longer filaments 2.5–4.5 mm, shorter ones 1.5–2.5 mm, anthers oblong, 1.2–1.6 × 0.7–1 mm, extrorse; ovary cylindric, subterete, 10–16 × 2–3 mm, glabrate to strigillose or villous; nectary disc slightly elevated at ovary apex, 2–4 mm diam., lobed, depressed, surrounded by densely matted white hairs; style 3–4.5 mm, glabrous, stigma capitate-globose, 1–1.5 × 2–2.5 mm, ± exserted beyond anthers. |
sepals ovate to lanceolate, 7–12 × 1.5–4 mm, apex acute or short acuminate, membranous, margins usually minutely scabrid, surfaces usually glabrous, sometimes puberulent abaxially; petals orbiculate-obovate, 10–20 × 10–18 mm, short-clawed; stamens 8 in 2 subequal series, yellow, filaments 1.3–2.5 mm, anthers oblong, 1.3–1.6 × 0.5–0.6 mm; ovary obconic, sharply 4-angled and 4-winged, 6–10 × 2–4.5 mm, glabrous or minutely puberulent; nectary disc plane on ovary apex, 3–5 mm diam., 4-lobed, glabrate or ringed with short hairs; style 2.5–3.2 × 0.5–0.6 mm, stigma globose, 1–2 × 1–2 mm, not exserted beyond anthers and pollen shed directly on it. |
Capsules | obscurely [4 or]5 or 6[or 7]-angled or subterete, straight or curved, 15–50 × 2.5–4 mm, relatively thin-walled, seeds visible as bumps, tardily and irregularly loculicidal, villous, pedicel 2–20 mm. |
rarely sharply curved, subclavate to oblong-obovoid or narrowly obpyramidal, sharply 4-angled and 4-winged, 10–25 × 3–5 mm, glabrous, pedicel 2–15 mm. |
Seeds | in 1 row per locule, horizontal and loosely embedded in an easily detached horseshoe-shaped segment of firm endocarp, pale brown, obovoid, 1–1.2 mm, shiny, finely pitted, raphe much narrower than seed body. |
oblong or subcylindric, 0.5–0.6 × 0.2 mm, striate, raphe very narrow and inconspicuous. |
2n | = 32, 48. |
= 16. |
Ludwigia leptocarpa |
Ludwigia decurrens |
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Phenology | Flowering summer. | Flowering summer–early fall. |
Habitat | Wet places, mainly along coastal areas, especially ditches, banks near brackish water. | Moist or swampy habitats along sloughs, muddy stream banks, marshy shores of lakes and ponds, ditches, swamps. |
Elevation | 0–200[–1300] m. (0–700[–4300] ft.) | 0–300[–600] m. (0–1000[–2000] ft.) |
Distribution |
AL; AR; DE; FL; GA; IL; IN; KY; LA; MD; MO; MS; NC; OH; OK; PA; SC; TN; TX; VA; WV; Central America; South America; Mexico (Campeche, Chiapas, Jalisco, Nayarit, Oaxaca, San Luis Potosí, Tabasco, Tamaulipas, Veracruz); West Indies (Cuba, Hispaniola, Jamaica, Puerto Rico); Africa; Indian Ocean Islands (Madagascar)
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AL; AR; DC; FL; GA; IL; KY; LA; MD; MO; MS; NC; OH; OK; PA; SC; TN; TX; VA; WI; WV; Central America; South America; Mexico (Campeche, Chiapas, Michoacán, Tabasco); West Indies; Bermuda [Introduced in Europe (France), e Asia (Japan), Africa (Cameroon), Pacific Islands (Philippines)]
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Discussion | Ludwigia leptocarpa is a globally widespread and morphologically variable species; in the flora area it is distributed widely in wet areas of the southeastern United States. Both tetraploid and hexaploid plants are known, but it is not clear if or how ploidy level is related to the considerable morphological variation, especially in pubescence type and pattern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ludwigia decurrens appears to be most closely related to L. erecta, differing by having winged, not angled, capsules and larger flowers, with sepals 7–12 mm and petals 10–20 mm (in L. erecta, sepals 3–6 mm, petals 3.5–5 mm). They often grow in close proximity and may hybridize, but hybrids would be difficult to detect. Ludwigia decurrens is often self-pollinating, but larger flowers may promote outcrossing. Ludwigia jussiaeoides Michaux is an illegitimate later homonym of L. jussiaeoides Desrousseaux and pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Seminudae | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Pterocaulon |
Sibling taxa | ||
Synonyms | Jussiaea leptocarpa, J. biacuminata, J. foliosa, J. leptocarpa subsp. angustissima, J. leptocarpa var. angustissima, J. leptocarpa var. meyeriana, J. pilosa, J. pilosa var. robustior, J. schottii, J. surinamensis, J. variabilis, J. variabilis var. meyeriana, J. variabilis var. pilosa, L. leptocarpa var. angustissima, L. leptocarpa var. meyeriana | Diplandra decurrens, D. montana, Jussiaea alata, J. bertonii, J. decurrens, J. palustris, J. pterophora, J. tenuifolia |
Name authority | (Nuttall) H. Hara: J. Jap. Bot. 28: 292. (1953) | Walter: Fl. Carol., 89. (1788) |
Web links |