Ludwigia octovalvis |
Ludwigia linifolia |
|
---|---|---|
Mexican primrose-willow |
flaxleaf seedbox, southeastern primrose-willow |
|
Habit | Herbs (robust)or shrubs, herbs tap-rooted, often woody at base, with peeling bark. | Herbs slender, rarely with aerenchyma, forming slender stolons 4–15(–30) cm, 0.7–1(–1.5) mm thick. |
Stems | erect to spreading, terete or sometimes ridged, 60–250(–400) cm, densely branched, densely villous to glabrate, especially near base. |
erect or ascending, slightly ridged, usually well branched, 12–55(–62) cm, glabrous. |
Leaves | 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. |
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. |
Inflorescences | 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. |
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. |
Flowers | 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. |
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. |
Capsules | 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. |
subcylindric, terete or slightly angled, 5–10(–12) ×1.3–2(–2.2) mm, hard-walled, irregularly dehiscent, pedicel 0 mm. |
Seeds | 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. |
reddish brown, oblong-elliptic, 0.6–0.7 × 0.2–0.3 mm, surface cells nearly isodiametric. |
2n | = [16], 32, 48. |
= 16. |
Ludwigia octovalvis |
Ludwigia linifolia |
|
Phenology | Flowering summer–early fall. | Flowering late Jun–Oct. |
Habitat | Wet or moist places, along coasts, streams, ditches, swamps, often near disturbance or cultivation. | Drainage ditches, margins of creeks or swamps, open edges of cypress swamps, moist pinelands, edges of brackish lakes. |
Elevation | 0–300[–2200] m. (0–1000[–7200] ft.) | 0–300 m. (0–1000 ft.) |
Distribution |
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)
|
AL; FL; GA; MS; NC; SC; Mexico (Tabasco) |
Discussion | 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.) |
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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Macrocarpon | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia |
Sibling taxa | ||
Synonyms | 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 | Isnardia linifolia |
Name authority | (Jacquin) P. H. Raven: Kew Bull. 15: 476. (1962) | Poiret in J. Lamarck et al.: Encycl., Suppl. 3: 513. (1814) |
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