Ludwigia brevipes |
Ludwigia alternifolia |
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Long Beach primrose-willow, ludwigiantha brevipes |
bushy seedbox, ludwigie à feuilles alternes, rattlebox, seedbox, square-pod water-primrose |
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Habit | Herbs creeping and rooting at nodes, sometimes forming large mats. | |
Roots | fusiform, fascicled, thickened, epidermis splitting or peeling near base. |
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Stems | prostrate, ascending or erect at tips, terete, well branched, 20–70 cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
subterete or somewhat angled, with narrow raised lines or wings decurrent from leaf axils, 40–150 cm, well branched in distal 1/2, glabrous or sparsely to densely strigillose. |
Leaves | 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. |
stipules narrowly deltate, 0.05–0.2 × 0.05–0.1 mm; petiole 0.1–0.3(–0.7) cm; blade lanceolate-elliptic, (0.6–)2–12 × (0.3–)1–1.5(–2.5) cm, base attenuate, margins entire, apex acute, surfaces strigillose throughout or glabrate with strigillose veins; bracts often reduced and more linear. |
Inflorescences | 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. |
leafy racemes, flowers solitary in leaf axils; bracteoles linear-lanceolate, 1–2.5 mm, margins entire, apex acute or subacuminate, glabrous or with scattered hairs, attached near base of ovary. |
Flowers | 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. |
sepals narrowly ovate-deltate, (6–)6.5–9.5 × 4–6.5 mm, margins entire, apex acute to obtuse, surfaces strigillose, sometimes mixed with villous hairs, or glabrate; petals cordate, 10–14 ×8–12 mm, base attenuate, apex emarginate; filaments opaque white, awl-shaped, 1–3 mm, anthers 1–1.7 × 0.6–0.8 mm; ovary subcuboid to globose, 2.5–4 ×2.5–3.5 mm; nectary disc slightly elevated on ovary apex, 0.8–1.5 mm diam., 4-lobed, ringed with soft, curly hairs or glabrous; style 1.5–2.4 mm, glabrous, stigma light yellow, capitate to hemispherical, 1–1.3 × 1.4–2 mm, shallowly 4-lobed, not or scarcely exserted beyond anthers. |
Capsules | 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. |
subcuboid to squarish globose, 4–6(–7) × 4–6 mm, 4-angled and 4-winged, wings 0.3–1.5 mm wide, pedicel 2–7 mm. |
Seeds | light to dark brown, ellipsoid, 0.6–0.7 × 0.3–0.5 mm, surface cells transversely elongate. |
light brown, oblong to reniform, 0.5–0.8 × 0.2–0.4 mm, surface cells elongate transversely to seed length. |
2n | = 48. |
= 16. |
Ludwigia brevipes |
Ludwigia alternifolia |
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Phenology | Flowering Jun–Sep. | Flowering summer–early fall. |
Habitat | Wet soil or sand along edges of ponds, lakes, marshes, or rivers, moist dune hollows, seasonal ponds. | Swamps, damp, peaty places, roadside ditches, margins of cultivated fields. |
Elevation | 0–200 m. (0–700 ft.) | 0–1800 m. (0–5900 ft.) |
Distribution |
FL; NC; NJ; SC; VA
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AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON; QC
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Discussion | 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.) |
Ludwigia alternifolia is widespread and common in the eastern half of the flora area, as far west as Ontario in Canada, eastern Colorado, and Texas. Ludwigia macrocarpa Michaux 1803 is a superfluous, illegitimate name for L. alternifolia. Rhexia linearifolia Poiret was originally described as a species of Melastomataceae, but the description is superficially similar to Ludwigia and has often been included in synonymy with L. alternifolia. The type of R. linearifolia has not been located or studied. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Ludwigia |
Sibling taxa | ||
Synonyms | Ludwigiantha brevipes | Isnardia alternifolia, I. alternifolia var. salicifolia, I. alternifolia var. uniflora, I. aurantiaca, L. alternifolia var. linearifolia, L. alternifolia var. pubescens, L. angustifolia var. ramosissima, L. aurantiaca, L. ramosissima, L. salicifolia, L. uniflora |
Name authority | (Long) Eames: Rhodora 35: 228. (1933) — (as Ludvigia) | Linnaeus: Sp. Pl. 1: 118. (1753) |
Web links |