Ludwigia peruviana |
Ludwigia lanceolata |
|
---|---|---|
Peruvian primrose-willow |
lanceleaf primrose-willow |
|
Habit | Herbs often woody at base, with peeling bark. | 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 | usually ridged, rarely succulent, profusely branched, 100–400 cm, usually villous, rarely glabrous, hairs deciduous in age, multicellular, usually tawny. |
erect, subterete or slightly ridged, well branched distally, 45–100 cm, glabrous, with raisedlines decurrent from leaf axils. |
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 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. |
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. |
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. |
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 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. |
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, 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. |
Seeds | brown or reddish brown, oblong, 0.6–0.9 × 0.3–0.4 mm, rounded at ends, with inconspicuous raphe. |
light brown, narrowly oblong with constricted ends, 0.6–0.8 ×0.2–0.3 mm, surface cells nearly isodiametric. |
2n | = 64, 80, 96, 128. |
= 32. |
Ludwigia peruviana |
Ludwigia lanceolata |
|
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, low meadows, cypress swamps, moist pinelands, edges of pocosins, sandy peaty soil. |
Elevation | 0–200[–2600] m. [0–700[–8500] ft.] | 0–100 m. [0–300 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]
|
FL; GA; NC; SC
|
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 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.) |
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 lanceolata |
Name authority | (Linnaeus) H. Hara: J. Jap. Bot. 28: 293. (1953) | Elliott: Sketch Bot. S. Carolina 1: 213. (1817) |
Web links |