Ludwigia grandiflora |
Ludwigia brevipes |
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large-flower primrose-willow, Uruguayan primrose-willow |
Long Beach primrose-willow, ludwigiantha brevipes |
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Habit | Herbs, subshrubs, or emergent aquatics, rooting at lower nodes, sometimes woody at base, white pneumatophores 8–10 cm often on submerged stems. | Herbs creeping and rooting at nodes, sometimes forming large mats. |
Stems | erect or ascending to creeping or floating, terete or sometimes angled distally, 20–300(–450) cm, usually densely branched, sometimes simple, glabrous if floating, or densely villous and viscid throughout, or rarely just on inflorescence. |
prostrate, ascending or erect at tips, terete, well branched, 20–70 cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
Leaves | stipules (rarely in clusters of 3), ovate-deltate, 0.6–2 × 0.6–1.5 mm, fleshy, apex subacute, often mucronate; petiole 0.1–1.1 cm; blade usually lanceolate to (narrowly) elliptic or oblanceolate, rarely narrowly obovate, (1.7–)3.1–8(–10.5) × 0.5–2(–2.5) cm, chartaceous, viscid, base cuneate or attenuate, margins entire, apex obtuse or acute, always glandular-mucronate, surfaces densely villous, sometimes less dense adaxially, distal leaves more pubescent than proximal ones; bracts scarcely 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 | on emergent stems sometimes in leafy racemes, flowers solitary in leaf axils; bracteoles narrowly to broadly obovate, 1–1.2 × 0.7–0.8 mm, succulent, apex acute, oppositely attached at ovary base. |
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 usually deciduous, not persistent on capsule, lanceolate, 6–12(–16) × 2–4 mm, chartaceous, apex acute, surfaces densely villous; petals yellow, fan-shaped, (12–)16–20(–26) × 11–16(–21) mm, apex rounded, usually emarginate, rarely mucronate; stamens 10(or 12), in 2 unequal series, yellow, filaments reflexed, shorter ones (2.8–)3.8–5.3 mm, longer ones (3.7–)6–6.5 mm, anthers oblong, 1–2.5 × (0.6–)0.8–1.2 mm; ovary subcylindric, terete, 6–12 × 1.5–2.5 mm, apex thickened, densely villous; nectary disc slightly raised on ovary apex, yellow, 1.5–2.5 mm diam., lobed, ringed with villous hairs; style yellow, 4.7–6.7(–8) mm, glabrous or sparsely pubescent near base, stigma subcapitate-globose, 1–1.3 × 1.6–2.5 mm, usually 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 | subcylindric, terete, straight or curved, (11–)14–25 × 3–4 mm, with thick woody walls, irregularly and tardily dehiscent, villous-viscid, pedicel 13–25(–27) 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 | embedded in wedge-shaped piece of endocarp, 0.8–1 × 0.8–0.9 mm. |
light to dark brown, ellipsoid, 0.6–0.7 × 0.3–0.5 mm, surface cells transversely elongate. |
2n | = 48. |
= 48. |
Ludwigia grandiflora |
Ludwigia brevipes |
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Phenology | Flowering summer. | Flowering Jun–Sep. |
Habitat | Wet places, along slow-moving rivers, streams, canals, ditches, often growing into main channel as aquatic weed. | Wet soil or sand along edges of ponds, lakes, marshes, or rivers, moist dune hollows, seasonal ponds. |
Elevation | 0–200[–1200] m. (0–700[–3900] ft.) | 0–200 m. (0–700 ft.) |
Distribution |
AL; AR; CA; FL; GA; KY; LA; MO; MS; NC; NJ; NY; OK; OR; PA; SC; TN; TX; VA; WA; WV; Central America (Guatemala); South America (Argentina, Bolivia, Brazil, Paraguay, Uruguay)
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FL; NC; NJ; SC; VA
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Discussion | Ludwigia grandiflora occurs in two disjunct areas: the southeastern United States on the coastal plain of southern South Carolina, Georgia, northern Florida, Louisiana, west to central Texas, and recently in southern California (P. C. Hoch and B. J. Grewell 2012) and Oregon; and central South America from south of the Amazon basin of Brazil and Bolivia where it is very scattered, to Uruguay, northeastern Argentina, and Paraguay where it is very frequent. It has been collected three times in Guatemala and twice in Missouri, although it is not clearly established in either region. It usually grows below 200 m elevation, but in Guatemala and in Santa Catarina, Brazil (Smith & , MO), it has been collected as high as Klein 133831200 m elevation. Populations of L. grandiflora in the United States are fairly variable, although not as much as in South American populations. As noted by Greuter and Burdet, the publication of Jussiaea grandiflora Ruíz & Pavon, which was a synonym of J. peruviana, occurred in 1830, not in 1802 as reported (P. A. Munz 1942; P. H. Raven 1963[1964]). Therefore, J. grandiflora Michaux in 1803 is legitimate, and J. grandiflora Ruíz & Pavon is an illegitimate homonym. (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. Jussiaea | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia |
Sibling taxa | ||
Synonyms | Jussiaea grandiflora, J. repens var. grandiflora, J. repens var. hispida, J. stenophylla, J. stuckertii, J. uruguayensis, L. clavellina var. grandiflora, L. uruguayensis | Ludwigiantha brevipes |
Name authority | (Michaux) Greuter & Burdet: Willdenowia 16: 448. (1987) | (Long) Eames: Rhodora 35: 228. (1933) — (as Ludvigia) |
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