Ludwigia curtissii |
Ludwigia octovalvis |
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Curtiss' primrose-willow |
Mexican primrose-willow |
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Habit | Herbs rarely creeping and rooting at nodes, stolons usually absent. | Herbs (robust)or shrubs, herbs tap-rooted, often woody at base, with peeling bark. |
Stems | erect or ascending at base, very rarely prostrate, unbranched to well branched, branches sometimes very slender, 15–75 cm, glabrous, with slightly raised lines decurrent from leaf axils. |
erect to spreading, terete or sometimes ridged, 60–250(–400) cm, densely branched, densely villous to glabrate, especially near base. |
Leaves | alternate; stipules reddish purple, narrowly ovate, 0.2–0.3 × 0.1–0.3 mm, succulent; petiole winged, 0.3–1.2 cm, blade usually oblanceolate-spatulate to spatulate or oblanceolate, rarely sublinear, 1–2.5(–3) × 0.1–0.8 cm, base attenuate, margins subentire with hydathodal glands, apex acute or mucronate, surfaces glabrous; bracts not reduced. |
stipules deltate, 0.5–0.8 × 0.6–0.7 mm, fleshy; petiole 0–1 cm; blade linear to oblong or oblanceolate, sometimes narrowly ovate, 0.7–14.5 × 0.1–4 cm, base tapered, margins entire, apex acute to acuminate, surfaces ± densely villous or strigillose; bracts not or scarcely reduced. |
Inflorescences | usually not congested, leafy racemes or spikes, flowers solitary in leaf axils; bracteoles attached in opposite pairs near base of ovary, narrowly lanceolate, lanceolate-elliptic, or oblong-linear, 1.5–3.5(–4) × 0.4–0.8 mm, swollen at base, apex acuminate. |
open, leafy racemes, flowers solitary in axils, presentation often radial; bracteoles ovate, 3–8 × 1.4–4 mm, apex acuminate, attached near base of ovary. |
Flowers | sepals ascending, green fading to white near base, ovate-deltate, 1.5–3 × 1.2–2 mm, margins entire, apex narrowly acute or acuminate, surfaces glabrous; petals 0(–3), narrowly elliptic or spatulate, 1–2.5 × 0.5–1 mm, base attenuate, apex obtuse; filaments pale yellow, 0.8–1(–1.3) mm, anthers 0.3–0.6 × 0.3–0.5 mm; pollen shed singly; ovary obovate-obpyramidal, 2–2.5 × 1.8–2.3 mm, glabrous; nectary disc elevated 0.3–0.4 mm on ovary apex, green, 0.9–1.6 mm diam., prominently 4-lobed, glabrous; style pale green, 0.4–0.7 mm, glabrous, stigma pale yellow, subglobose, 0.3–0.4 × 0.2–0.4 mm, not exserted beyond anthers. |
sepals lanceolate to ovate, (6–)8–13 × 3–7 mm, apex acuminate, surfaces strigillose adaxially; petals bright yellow, fan-shaped, (5–)10–20 × 5–20 mm, apex sometimes shallowly notched; stamens 8 in 2 subequal series, yellowish white, filaments spreading, 4–6 mm, anthers oblong, 2.5–5 × 1–2 mm; pollen shed in tetrads or sometimes polyads; ovary cylindric, 4-angled, sometimes slightly twisted, 8–22 × 1–3 mm; nectary disc elevated 0.4–0.5 mm on ovary apex, 1–2.4 mm diam., with 4 white-pubescent sunken lobes opposite petals; style 2.5–3.5 mm, stigma capitate-globose, 1.8–3.5 × 2.5–3.5 mm, surrounded by anthers and pollen shed directly on it. |
Capsules | obconic, obscurely 4-angled, (2–)2.5–4(–4.7) × 2–3(–3.5) mm, hard-walled, dehiscent by loculicidal slits, pedicel 0.1–0.5 mm. |
cylindric to clavate-cylindric, subterete to ± 4-angled, 17–50 × 2.5–8 mm, thin-walled, irregularly dehiscent by 4–8 linear valves splitting from apex, short-villous, pedicel 5–25 mm. |
Seeds | light brown, ellipsoid, 0.4–0.6 × 0.3–0.4 mm, surface cells transversely elongate, glabrous or, sometimes, with surface wax that mimics appressed hairs. |
in several indistinct rows per locule, broad-cylindric with rounded ends, 0.6–0.9 × 0.5–0.8 mm, raphe inflated and nearly equal to seed body. |
2n | = 64. |
= [16], 32, 48. |
Ludwigia curtissii |
Ludwigia octovalvis |
|
Phenology | Flowering Mar–Nov (year-round). | Flowering summer–early fall. |
Habitat | Pine savannas and flatwoods, marshes, edges of ponds and streams, sandy or peaty swales, limestone prairies, solution pits on limestone. | Wet or moist places, along coasts, streams, ditches, swamps, often near disturbance or cultivation. |
Elevation | 0–50 m. (0–200 ft.) | 0–300[–2200] m. (0–1000[–7200] ft.) |
Distribution |
FL; West Indies (Bahamas) |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America; West Indies; s Asia; e Asia (Burma, China, India, Japan, Thailand, Vietnam); Africa; Indian Ocean Islands (Comoros Islands, Madagascar); Pacific Islands (New Caledonia, Papua New Guinea, Philippines)
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Discussion | Ludwigia curtissii is the only octoploid (n = 32) in sect. Isnardia, and is restricted to peninsular Florida and the Bahamas. It and L. simpsonii they are the only members of the section that do not form true stolons; instead they simply sprout new shoots from the base. The two species are similar in many ways and appear to share three genomes (C. I. Peng 1988). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ludwigia octovalvis is perhaps the most widespread species of Ludwigia worldwide and exhibits a very complex pattern of morphological and ecological variation, correlated only in part with multiple ploidy levels; this complexity is reflected in its extensive synonymy. P. H. Raven (1963[1964]), P. A. Munz (1942, 1965), and others have proposed formal classifications to account for this variation, with mixed results and additional study using more powerful analytical tools is clearly needed in order to develop a more stable classification. In the absence of better understanding, and despite some correlated patterns of morphological and geographical variation on a global scale, this treatment does not recognize infraspecific taxa. Jussiaea hirsuta Velloso, J. suffruticosa var. angustifolia Chodat & Hassler, J. velutina Kunze, and Ludwigia suffruticosa (Linnaeus) M. Gómez are later homonyms; these four names pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | L. spathulifolia | Oenothera octovalvis, Jussiaea calycina, J. clavata, J. frutescens, J. haenkeana, J. hirta, J. ligustrifolia, J. occidentalis, J. octofila, J. octonervia, J. octonervia var. sessiliflora, J. octovalvis, J. parviflora, J. peruviana var. octofila, J. pubescens, J. sagrana, J. salicifolia, J. scabra, J. suffruticosa, J. suffruticosa var. ligustrifolia, J. suffruticosa var. linearifolia, J. suffruticosa var. octofila, J. suffruticosa subsp. octonervia, J. suffruticosa var. octonervia, J. suffruticosa var. sessiliflora, J. suffruticosa var. sintenisii, J. venosa, J. villosa, L. octovalvis var. ligustrifolia, L. octovalvis var. octofila, L. octovalvis subsp. sessiliflora, L. octovalvis var. sessiliflora, L. pubescens, L. pubescens var. ligustrifolia, L. pubescens var. linearifolia, L. pubescens var. sessiliflora, L. sagrana |
Name authority | Chapman: Fl. South. U.S. ed. 2, 621. (1883) | (Jacquin) P. H. Raven: Kew Bull. 15: 476. (1962) |
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