Ludwigia peruviana |
Ludwigia alata |
|
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Peruvian primrose-willow |
wing primrose-willow |
|
Habit | Herbs often woody at base, with peeling bark. | Herbs with aerenchyma when base submerged, forming stolons from lower nodes, 8–65(–95) cm, 0.7–2.5 mm thick. |
Stems | usually ridged, rarely succulent, profusely branched, 100–400 cm, usually villous, rarely glabrous, hairs deciduous in age, multicellular, usually tawny. |
erect or somewhat sprawling, slightly to distinctly winged (wings to 1.8 mm wide), branched distally, 40–120(–160) cm, glabrous. |
Leaves | stipules deciduous, narrowly deltate, 1–1.5 × 0.3–0.5 mm, setaceous; petiole 0–1.5 cm; blade usually lanceolate, elliptic or broadly elliptic, sometimes ovate, obovate, or rounded, 2–45 × 1–10 cm, base obtuse or cuneate, rarely asymmetrical, margins entire or gland-toothed, apex usually acute or acuminate, rarely rounded and emarginate, mostly scabrid, membranous or papery, surfaces usually villous, sometimes glabrous; bracts usually not strongly reduced. |
alternate; stipules ovate-deltate, often narrowly so, 0.2–0.4 × 0.1–0.3 mm, succulent; stolons: petiole 0.15–1 cm, blades orbiculate to oblanceolate or broadly elliptic, 0.4–2.6 × 0.4–1.5 cm, base attenuate, apex rounded to subacute; stems: petiole 0–0.3 cm, blade lanceolate-elliptic or very narrowly elliptic to linear, sometimes to oblanceolate or oblanceolate-elliptic near base, 1.8–10 × 0.2–1.3(–2) cm, base narrowly cuneate or attenuate, margins subentire with remote hydathodal glands, rarely minutely papillose-serrulate near apex, apex acute to narrowly acute, leaves on side branches much reduced; bracts much reduced. |
Inflorescences | leafy racemes, flowers solitary in distal axils; bracteoles deciduous, usually attached near base or on lower 1/2 of ovary, sometimes on upper pedicel, subtended by reduced, glandlike stipels, ovate or lanceolate to linear, 5–20 × 1–6 mm, apex acute or short-acuminate, surfaces villous. |
sometimes congested, leafy spikes or racemes, flowers solitary in distal leaf axils; bracteoles attached near base of ovary, lanceolate-elliptic or narrowly so, 2.4–4.7 × 0.6–1.5 mm, margins minutely papillose or smooth, apex acute, surfaces glabrous. |
Flowers | sepals ovate or ovate-lanceolate, 10–23 × 4–9 mm, apex acute or short-acuminate, sometimes glandular-serrulate; petals bright yellow, orbiculate or obovate, 10–40 × 10–40 mm, apex rarely emarginate, short-clawed; stamens 8(or 10) in 2 unequal series, yellow, shorter filaments 1.5–4 mm, longer ones 3.5–5 mm, anthers oblong, 3–6 mm; ovary obconic, 4- or 5-angled, sometimes subterete, 5–20 × 3–7 mm, narrowed to pedicel, usually densely villous, sometimes glabrous; nectary disc elevated 0.3–3.2 mm on ovary apex, 4–6 mm diam., 4(or 5)-lobed, sunken, ringed by long, white hairs; style 1.5–3.5 mm, stigma globose, 1.6–3.5 × 1.8–3.5 mm, usually as long as stamens, rarely exserted beyond them. |
sepals spreading to reflexed, creamy white adaxially, broadly ovate-deltate, 2–4 × 1.6–4 mm, margins smooth or minutely papillose-serrulate, apex acute or acuminate, surfaces glabrous; petals 0; filaments nearly translucent, 1.1–1.7 mm, slightly dilated near base, anthers 0.5–0.9 × 0.4–0.7 mm; pollen shed singly; ovary obpyramidal, sharply 4-angled, 2–3.8 × 2–3.5 mm; nectary disc elevated 0.5–0.8 mm on ovary apex, bright yellow, square with rounded corners, 2–3.3 mm diam., prominently 4-lobed, glabrous; style pale green, 0.8–1.3 mm, glabrous, stigma pale yellow, subglobose, 0.3–0.6 × 0.3–0.7 mm, shallowly 4-lobed on top, not exserted beyond anthers. |
Capsules | ± sharply 4- or 5-angled, 10–40 × 6–13 mm, thin-walled, irregularly dehiscent, pedicel 5–65 mm. |
obpyramidal, sharply 4-angled and 4-winged, 3–5 × 2.8–4.5 mm, with hard walls somewhat bulging, dehiscent by apical ring, pedicel 0–0.8 mm. |
Seeds | brown or reddish brown, oblong, 0.6–0.9 × 0.3–0.4 mm, rounded at ends, with inconspicuous raphe. |
light brown, ellipsoid, slightly curved on both ends, 0.6–0.7 × 0.3–0.4 mm, surface cells elongate transversely to seed length. |
2n | = 64, 80, 96, 128. |
= 48. |
Ludwigia peruviana |
Ludwigia alata |
|
Phenology | Flowering Jun–Aug(–Sep) (sometimes in any month). | Flowering Jun–Oct. |
Habitat | Wet places, ditches, drainage canals, sloughs, swales, marshy shores, wet clearings. | Ditches, edges of ponds and lagoons, peaty or sandy swales, open cypress swamps, sandy borrow pits in open pine woods, swampy, flat outcrops of oolitic rocks, wet savannas, tidal flats, brackish marshes, sandy beach strands and hammocks. |
Elevation | 0–200[–2600] m. [0–700[–8500] ft.] | 0–50 m. [0–160 ft.] |
Distribution |
AL; FL; GA; NC; TX; Central America; South America; Mexico (Chiapas, Durango, Oaxaca, Puebla, Tabasco, Veracruz); West Indies [Introduced in Eurasia (India, Indonesia, Singapore, Sri Lanka), Australia]
|
AL; FL; GA; LA; MS; NC; SC; VA; West Indies (Jamaica) |
Discussion | Ludwigia peruviana is sometimes cultivated and naturalized, which may account for occurrences in North America and Eurasia. Except in the Amazon basin, where it is known only from few collections in western Amazonia, and in northeastern Brazil, where it is scarce, L. peruviana is common throughout its range, and may behave as a weed, especially along slow-flowing canals and drainage ditches. Ludwigia peruviana is also naturalized at scattered localities in Asia (P. H. Raven 1963[1964]) and around Sydney, Australia. The earliest collection from Asia is labeled “ex horto bot. Bogoriensi Javae misit 1869” (Raven). It also occurs locally in the Nilgiri Mountains of southwest India and in Sri Lanka, as well as in scattered locations in Bangka, Java, Malaysia, and Sumatra from sea level to 1000 m (Raven 1963[1964], 1978). Jussiaea grandiflora Ruíz & Pavon, a synonym for J. peruviana Linnaeus, appeared in 1830, not in 1802 (P. A. Munz 1942; P. H. Raven 1963[1964]); it is a later homonym of J. grandiflora Michaux (1803), as reported in W. Greuter and T. Raus (1987). Jussiaea hirta (Linnaeus) Swartz is an illegitimate homonym and J. hirta (Linnaeus) Vahl is an illegitimate isonym; both pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ludwigia alata occurs only at very low elevations along the Atlantic and Gulf coastal plains from Virginia to the tip of Florida, and west to southwestern Louisiana, with disjunct populations on Jamaica (C. I. Peng 1989). This hexaploid species is often confused with L. lanceolata, with which it shares two genomes (Peng 1988, 1989) and with which it is frequently sympatric. The showy petals of L. alata suggest a higher level of outcrossing, and numerous natural hybrids have been documented (Peng 1988, 1989). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Jussiaea peruviana, J. hirsuta, J. macrocarpa, J. mollis, J. peruviana var. glaberrima, J. speciosa, J. sprengeri, L. hirta, Oenothera hirta | Isnardia alata |
Name authority | (Linnaeus) H. Hara: J. Jap. Bot. 28: 293. (1953) | Elliott: Sketch Bot. S. Carolina 1: 212. (1817) |
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