Ludwigia linifolia |
Ludwigia peruviana |
|
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flaxleaf seedbox, southeastern primrose-willow |
Peruvian primrose-willow |
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Habit | Herbs slender, rarely with aerenchyma, forming slender stolons 4–15(–30) cm, 0.7–1(–1.5) mm thick. | Herbs often woody at base, with peeling bark. |
Stems | erect or ascending, slightly ridged, usually well branched, 12–55(–62) cm, glabrous. |
usually ridged, rarely succulent, profusely branched, 100–400 cm, usually villous, rarely glabrous, hairs deciduous in age, multicellular, usually tawny. |
Leaves | alternate; stipules narrowly ovate to narrowly lanceolate, 0.2–0.3 × 0.1–0.2 mm; stolons: petiole narrowly attenuate, 0.05–0.5 cm, blade narrowly obovate or oblanceolate to spatulate, 0.5–2 × 0.1–0.6 cm; stems: sessile, blade linear to linear-oblanceolate, 1.5–4 × 0.1–0.4(–0.6) cm, base very narrowly cuneate, margins entire with obscure hydathodal glands, apex acuminate to acute; bracts linear, reduced. |
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. |
Inflorescences | leafy spikes, flowers solitary in leaf axils; bracteoles attached 0–1.5 mm distal to base of ovary, very narrowly oblanceolate to linear, (1.5–)2.5–9(–13) × 0.2–0.8 mm, margins entire, apex acute. |
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. |
Flowers | sepals ascending, green, narrowly lanceolate-deltate, (3–)4–7 × 1.1–1.7 mm, margins entire, apex narrowly acute, surfaces glabrous or minutely papillose; petals narrowly obovate-elliptic, 4–6 × 2–4 mm, base obtuse, apex obtuse or rounded; filaments pale yellow, (1.3–)1.5–2.5(–3) mm, anthers oblong, 0.6–1.1 × 0.5–0.8 mm; pollen shed in tetrads; ovary subcylindric, 3–4 × 1–1.5 mm; nectary disc elevated 0.3–0.7 mm on ovary apex, bright yellow, 0.8–1.5 mm diam., prominently 4-lobed, minutely papillose; style yellow, 1.25–2.5 mm, glabrous, stigma subcapitate, 0.3–0.6 × 0.6–0.8 mm, shallowly 4-lobed, not exserted beyond anthers. |
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. |
Capsules | subcylindric, terete or slightly angled, 5–10(–12) ×1.3–2(–2.2) mm, hard-walled, irregularly dehiscent, pedicel 0 mm. |
± sharply 4- or 5-angled, 10–40 × 6–13 mm, thin-walled, irregularly dehiscent, pedicel 5–65 mm. |
Seeds | reddish brown, oblong-elliptic, 0.6–0.7 × 0.2–0.3 mm, surface cells nearly isodiametric. |
brown or reddish brown, oblong, 0.6–0.9 × 0.3–0.4 mm, rounded at ends, with inconspicuous raphe. |
2n | = 16. |
= 64, 80, 96, 128. |
Ludwigia linifolia |
Ludwigia peruviana |
|
Phenology | Flowering late Jun–Oct. | Flowering Jun–Aug(–Sep) (sometimes in any month). |
Habitat | Drainage ditches, margins of creeks or swamps, open edges of cypress swamps, moist pinelands, edges of brackish lakes. | Wet places, ditches, drainage canals, sloughs, swales, marshy shores, wet clearings. |
Elevation | 0–300 m. (0–1000 ft.) | 0–200[–2600] m. (0–700[–8500] ft.) |
Distribution |
AL; FL; GA; MS; NC; SC; Mexico (Tabasco) |
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]
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Discussion | Ludwigia linifolia is primarily a coastal species that extends farther inland in Georgia and the Carolinas. Being one of five diploids in sect. Isnardia, it has particularly prominent nectary lobes and appears to be modally outcrossing (C. I. Peng 1989). It also is known from a disjunct population on the Yucatán Peninsula in Tabasco, Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Isnardia linifolia | Jussiaea peruviana, J. hirsuta, J. macrocarpa, J. mollis, J. peruviana var. glaberrima, J. speciosa, J. sprengeri, L. hirta, Oenothera hirta |
Name authority | Poiret in J. Lamarck et al.: Encycl., Suppl. 3: 513. (1814) | (Linnaeus) H. Hara: J. Jap. Bot. 28: 293. (1953) |
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