Ludwigia grandiflora
Ludwigia spathulata
large-flower primrose-willow, Uruguayan primrose-willow
southern water purslane, spoon primrose-willow
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 or decumbent and ascending distally, slightly ridged, well branched, 10–40cm, densely strigillose throughout.
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 or ovate, 0.05–0.15 × 0.05–0.1 mm;
petiole very narrowly winged, 0.3–0.9 cm, blade elliptic-spatulate or narrowly so, 0.9–1.7 × 0.3–0.9 cm, base attenuate, margins entire, apex acute, surfaces strigillose;
bracts not reduced except at branch tips.
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.
leafy spikes or racemes, flowers usually paired in leaf axils;
bracteoles attached at base of ovary or on short pedicel, narrowly oblong or oblanceolate, 0.2–0.8 × 0.05–0.2 mm, apex acute, often obscured by hairs.
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 ascending, pale green, broadly ovate-deltate, 1–1.7 × 1.1–1.7 mm, margins entire, apex acuminate, surfaces densely strigillose;
petals 0;
filaments translucent, 0.5–0.8 mm, anthers 0.2–0.4 × 0.3–0.5 mm;
pollen shed singly;
ovary oblong-obovoid, 4-angled to subterete, 1.5–2.5 × 1–1.5 mm;
nectary disc elevated 0.1–0.2 mm on ovary apex, yellowish green, 0.7–0.9 mm diam., 4-lobed, glabrous;
style yellowish green, 0.3–0.5 mm, glabrous, stigma pale yellow, capitate, 0.2–0.3 × 0.2–0.3 mm, not exserted beyond anthers.
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.
oblong-obovoid, subterete, 2.5–4(–4.5) × 1.5–2.5 mm, thin-walled, seeds often visible on exocarp as small bumps, irregularly dehiscent or dispersing as unit, pedicel 0–0.5 mm.
embedded in wedge-shaped piece of endocarp, 0.8–1 × 0.8–0.9 mm.
dark reddish brown, ellipsoid, 0.5–0.7 × 0.4–0.5 mm, surface cells transversely elongate.
= 48.
= 32.
Ludwigia grandiflora
Ludwigia spathulata
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.)
Flowers May–Sep. Ditches, swales, edges of ponds, lakes, sinks, swamps, sandy river bars, dried seasonal ponds, disturbed low savannas; of conservation concern; 0–200 m; Ala., Fla., Ga., S.C.
The tetraploid Ludwigia spathulata is relatively uncommon and occurs primarily on the Gulf Coastal Plain in the panhandle of Florida, southern Alabama, and southwestern Georgia. Outlying populations have also been collected in transitional areas between the Coastal Plain and the Piedmont in South Carolina and Georgia. With its small apetalous flowers, L. spathulata is modally autogamous and shows low morphological variability. Its strongest affinities appear to be with L. palustris, with which it shares a genome (C. I. Peng 1988, 1989).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
LA Plants
MO Plants
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
