Ludwigia repens

J. R. Forster

Fl. Amer. Sept., 6. 1771. (as Ludvigia), name conserved

Common names: Creeping primrose-willow red ludwigia
Synonyms: Isnardia intermedia Small & Alexander I. natans (Elliott) Kuntze I. repens de Candolle I. repens var. rotundata Grisebach Ludwigia fluitans Scheele L. natans Elliott L. natans var. rotundata (Grisebach) Fernald & Griscom L. natans var. stipitata Fernald & Griscom L. repens var. rotundata (Grisebach) M. Gómez L. repens var. stipitata (Fernald & Griscom) Munz
Treatment appears in FNA Volume 10.

Herbs creeping and rooting at nodes, often forming loose mats. Stems prostrate, ascending to suberect at tips, terete, sparsely branched, 30–80 cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. Leaves opposite; stipules narrowly deltate, 0.05–0.1 × 0.05–0.1 mm; petiole narrowly winged, 0.3–2.3 cm, blade narrowly elliptic to broadly lanceolate-elliptic or suborbiculate, 0.8–4.5 × 0.4–2.7 cm, base attenuate, margins entire or sometimes with hydathodal glands, apex acute or apiculate, rarely obtuse, surfaces lustrous, subglabrous or sparingly to densely papillose strigillose; bracts not much reduced. Inflorescences sometimes few-flowered, erect racemes, flowers paired in leaf-axils of prostrate stems; bracteoles attached in opposite pairs to pedicel 1–5 mm proximal to base of ovary, lanceolate to narrowly oblong-lanceolate or sublinear, 1–5 (–8) × 0.2–1 mm, apex acute, surfaces sparingly minutely strigillose. Flowers: sepals ascending, light green, ovate deltate to narrowly so, 1.8–5 × 1.5–3.5 mm, margins minutely strigillose, apex acuminate to elongate-acuminate, surfaces subglabrous; petals caducous, oblanceolate to elliptic-oblong, 1.1–3 × 0.4–1.4 mm, base attenuate, apex obtuse, often variable in size and shape in same flower; filaments pale-yellow, 0.5–1.5 mm, slightly inflated near base, anthers 0.4–0.9 × 0.3–0.8 mm; pollen shed singly or in tetrads; ovary obconic-cylindric, barely 4-angled to subterete, 2–6 × 2.5–3.5 mm; nectary disc elevated 0.3–0.8 mm on ovary apex, yellow, 1.1–3 mm diam., 4-lobed, glabrous; style pale-yellow, 0.6–0.9 mm, glabrous, stigma pale-yellow, broadly capitate, 0.3–0.5 × 0.3–0.8 mm, usually not exserted beyond anthers. Capsules elongate-obpyramidal, 4-angled, corners sometimes rounded, 4–10 × 2.5–4 mm, hard-walled, irregularly dehiscent, pedicel 0.1–3 mm. Seeds yellowish-brown, ellipsoid, 0.6–0.8 × 0.3–0.5 mm, surface cells transversely elongate. 2n = 48.

Discussion

Flowers Mar–Nov (year-round). Muddy or damp, sandy edges of pools, lakes, swamps, creeks, and roadside ditches, moist soil in solution pits in limerock and hammock clearings in Florida Everglades, shade or sun; 0–1200[–1600] m; Ala., Ariz., Calif., Fla., Ga., Kans., La., Miss., Nev., N.J., N.Mex., N.C., Okla., Oreg., S.C., Tenn., Tex., Va.; Mexico (Chihuahua, Coahuila, México, Morelos, Nuevo León, Puebla, San Luis Potosí, Sonora); West Indies (Bahamas, Cuba, Hispaniola, Jamaica); Bermuda; introduced in Asia (Bangladesh, Japan).

Ludwigia repens occurs primarily on the Atlantic and Gulf coastal plains of the United States from North Carolina to Texas, with more scattered distribution into west Texas, New Mexico, Oklahoma, and Kansas, and disjunct populations in New Jersey, Tennessee, southern Arizona, Nevada, California, and western Oregon (Marion County); it also occurs in northern and central Mexico and the Caribbean region. In some parts of this wide range it is considered an aquatic weed.

Ludwigia repens is one of the most popular species of Ludwigia used in the aquarium trade; this may help to account for its wide distribution.

Much like the related diploid Ludwigia palustris, the hexaploid L. repens is widespread and morpho­logically variable, and infraspecific taxa have been proposed to describe this variation. Given the tendency of species in sect. Isnardia to hybridize, and the lack of a geographical basis for much of the variation, C. I. Peng (1989) declined to adopt any infraspecific classification, and this treatment follows Peng.

As described in C. I. Peng et al. (2005), Ludwigia repens J. R. Forster was conserved with a new type (the original type selected was from Virginia, where the species does not occur); L. repens Swartz (1797) was a later homonym described from Jamaica and pertains here.

Selected References

None.

Lower Taxa

None.
... more about "Ludwigia repens"
3(-5)-aperturate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
variable +, obtuse +, acuminate +  and elongate-acuminate +
Peter C. Hoch +
J. R. Forster +
0.8 cm8 mm <br />0.008 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
attenuate +, suborbiculate +  and lanceolate-elliptic +
0.4cm;2.7cm +
Isnardia +
indehiscent +  and loculicidal +
lobed +, toothed +  and entire +
reduced +
reduced +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
dark red +  and black +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
lanceolate +  and narrowly oblong-lanceolate or sublinear +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
straight +  and slightly curved +
spreading +  and erect +
4-angled +  and elongate-obpyramidal +
Creeping primrose-willow +  and red ludwigia +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
North America +, Mexico +, West Indies +, Central America +, n South America +, e Asia +, in Eurasia +, Africa +, Pacific Islands +  and Australasia +
basifixed +  and versatile +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
long-pedicellate +  and subsessile +
straight +  and slightly curved +
by a terminal pore +  and dehiscent +
spreading +  and erect +
cylindric +  and clavate turbinate obpyramidal or globose +
apiculate +  and acute +
perennial +
glandular-puberulent +, hirtellous +, villous +  and strigillose +
deciduous +
0.8 cm8 mm <br />0.008 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
strigillose +
attenuate +, suborbiculate +  and lanceolate-elliptic +
0.4cm;2.7cm +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
barely 4-angled +  and subterete +
2.5mm +  and 3.5mm +
numerous +  and 1 +
submerged +
swollen +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
1.1mm +  and 3mm +
5 +  and 4 +
oblanceolate +  and elliptic-oblong +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (2.3 cm23 mm <br />0.023 m <br />) +
Fl. Amer. Sept., +
paired +, solitary +  and cluster +
inconspicuous +
expanded +
basal +  and cauline +
clavate +  and globose +
yellowish-brown +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
50 +  and 400 +
pitted +  and smooth +
ellipsoid +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
light green +
persistent +
post-anthesis +
5 +  and 4 +
deltate +  and ovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
parenchymatous +
parietal +, axile +  and placentation +
2 +  and 1 +
unequal +  and subequal +
2 times as many as sepals +
aquatic +, amphibious +  and terrestrial +
lenticular +
2 times as many as sepals +
ascending +  and suberect +
strigillose +, , +  and glabrous +
30 cm300 mm <br />0.3 m <br /> (80 cm800 mm <br />0.8 m <br />) +
pale-yellow +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
hemispherical +, capitate +, lobed +  and entire +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
sessile +  and petiolate +
green +  and dark reddish +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.01 cm0.1 mm <br />1.0e-4 m <br />) +
intrapetiolar +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.01 cm0.1 mm <br />1.0e-4 m <br />) +
pale-yellow +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
aquatic +, amphibious +  and terrestrial +
subglabrous +, strigillose +, subglabrous or +  and sparingly densely papillose strigillose +
papillate +
Isnardia intermedia +, I. natans +, I. repens +, I. repens var. rotundata +, Ludwigia fluitans +, L. natans +, L. natans var. rotundata +, L. natans var. stipitata +, L. repens var. rotundata +  and L. repens var. stipitata +
Ludwigia repens +
Ludwigia sect. Isnardia +
species +
3(-5)-aperturate +