Ludwigia bonariensis |
Ludwigia lanceolata |
|
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Carolina primrose-willow |
lanceleaf primrose-willow |
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Habit | Herbs, from woody rootstock. | Herbs slender, with well-developed aerenchyma when base submerged, often forming stolons 10–40 cm, 2–3 mm thick, stolons with widely spaced leaves. |
Stems | erect, subterete, 20–120 cm, branched, glabrate proximally, or strigillose, especially in distal parts, with raised strigillose lines decurrent from leaf axils mid stem. |
erect, subterete or slightly ridged, well branched distally, 45–100 cm, glabrous, with raisedlines decurrent from leaf axils. |
Leaves | stipules narrowly deltate, 0.3–0.5 × 0.1–0.2 mm; petiole winged, 0.1–0.7 cm; blade narrowly to broadly lanceolate, 4–15 × 0.3–1(–3) cm, base tapered, margins subentire to inconspicuously glandular-serrulate, apex acute to acuminate, surfaces finely strigillose, especially on abaxial veins, sometimes glabrate; bracts narrower, reduced in size. |
alternate; stipules ovate to very broadly ovate, 0.2–0.5 ×0.1–0.3 mm, succulent; stolons: petiole winged, 0.2–1 cm, blade orbiculate or elliptic to broadly elliptic, 0.5–2.7 × 0.6–1.2 cm, base attenuate, apex rounded to acute; main stem: petiole winged, 0.1–0.5 cm, blade elliptic, oblanceolate, or narrowly oblanceolate to sublinear, 2–7.5 × 0.2–0.8(–1.4) cm, base narrowly cuneate, sometimes attenuate, margins entire with minute hydathodal glands, apex acute to narrowly acute, leaves on side branches much reduced; bracts sublinear, moderately reduced. |
Inflorescences | open, leafy racemes, flowers solitary in axils; bracteoles lanceolate-linear or setaceous, 2–6 × 0.3–0.8 mm, attached on pedicel just proximal to base of ovary. |
open spikes, flowers solitary in distal leaf axils; bracteoles attached in opposite pairs at or slightly distal to base of ovary, ovate-elliptic to very narrowly elliptic, 1.5–4.3 × 0.4–1.4 mm, often with a swollen base, margins minutely papillose, apex subacute. |
Flowers | sepals ovate-deltate, 10–20 × 7–12 mm, abruptly acuminate or acute, inconspicuously 5–7-nerved, surfaces strigillose; petals deep golden yellow, broadly obovate, 20–35 × 10–30 mm, apex shallowly emarginate, claw 1.5–3 mm; stamens 8 in 2 unequal series, filaments flattened and dilated near base, epipetalous set 3.4–4.5 mm, episepalous set 4.5–5.5 mm, anthers oblong, 4–5 mm; pollen shed in polyads; ovary subcylindric, slightly 4-angled, 8–12(–20) mm; nectary disc slightly elevated on ovary apex, 2–3 mm diam., 4-lobed, ringed by short hairs; style 3–3.5 mm, stigma clavate-capitate, 2.5–3 × 2–2.5 mm, often exserted beyond anthers. |
sepals ascending, pale green, broadly ovate-deltate, 1.5–2.5 × 1.8–3.3 mm, margins minutely papillose, apex usually acute, rarely acuminate, surfaces glabrous; petals 0; filaments nearly translucent, 1–1.4 mm, base dilated, anthers 0.4–0.6(–0.8) × 0.5–0.6 mm; pollen shed in tetrads; ovary broadly obovoid or cup-shaped, 2.5–3.5 × 2.2–3.2 mm; nectary disc elevated 0.4–0.6 mm on ovary apex, yellowish green, 1.8–2.6 mm diam., 4-lobed, glabrous; style yellowish green, 0.5–0.7 mm, glabrous, stigma yellowish green, broadly capitate to subglobose, 0.3–0.5 × 0.7–1 mm, not exserted beyond anthers. |
Capsules | clavate-cylindric, subterete to obtusely 4-angled, 20–35 × 3.5–5 mm, thin walls, irregularly dehiscent, tapering to pedicel 10–40 mm. |
obpyramidal, sharply 4-angled and 4-winged, wings 0.3–0.7mm wide, 3.5–5 × 2.5–4.5 mm, hard-walled, dehiscent by apical ring, pedicel 0.1–0.5 mm. |
Seeds | in several indistinct rows per locule, yellow-brown, oblong (appearing round), 0.5 mm, shiny, raphe 2/3 as wide as body. |
light brown, narrowly oblong with constricted ends, 0.6–0.8 ×0.2–0.3 mm, surface cells nearly isodiametric. |
2n | = 16. |
= 32. |
Ludwigia bonariensis |
Ludwigia lanceolata |
|
Phenology | Flowering summer. | Flowering Jun–Oct. |
Habitat | Wet places, mainly along coastal areas, especially ditches, banks near brackish water. | Ditches, low meadows, cypress swamps, moist pinelands, edges of pocosins, sandy peaty soil. |
Elevation | 0–200[–2600] m. (0–700[–8500] ft.) | 0–100 m. (0–300 ft.) |
Distribution |
AL; FL; MS; NC; SC; TX; Mexico (Chihuahua, Durango, Puebla, Quintana Roo, Tabasco, Tamaulipas, Veracruz); South America (Argentina, Bolivia, Brazil, Paraguay, Uruguay)
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FL; GA; NC; SC
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Discussion | Ludwigia lanceolata is fairly uncommon, with scattered populations occurring along the Atlantic coast of southern North Carolina, South Carolina, eastern and southern Georgia, and peninsular Florida. It reaches its western limit in the central panhandle of Florida. C. I. Peng (1988, 1989) found this tetraploid species to be interfertile with other tetraploid species in the section, but few natural hybrids are found, perhaps due to persistent autogamy and habitat specialization. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Jussiaea bonariensis, J. neglecta, J. suffruticosa var. bonariensis | Isnardia lanceolata |
Name authority | (Micheli) H. Hara: J. Jap. Bot. 28: 291. (1953) | Elliott: Sketch Bot. S. Carolina 1: 213. (1817) |
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