Ludwigia linifolia |
Ludwigia hirtella |
|
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flaxleaf seedbox, southeastern primrose-willow |
hairy seedbox, Rafinesque's seedbox, spindleroot |
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Habit | Herbs slender, rarely with aerenchyma, forming slender stolons 4–15(–30) cm, 0.7–1(–1.5) mm thick. | |
Roots | fusiform, somewhat thickened, often fascicled. |
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Stems | erect or ascending, slightly ridged, usually well branched, 12–55(–62) cm, glabrous. |
subterete to angled, with raised lines or narrow wings decurrent from leaf axils, (30–)50–120 cm, well branched in distal 1/2, densely erect-hirsute to sometimes glabrous. |
Leaves | 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. |
stipules narrowly deltate, 0.05–0.15 × 0.05–0.1 mm; sessile; blade closely appressed to stem, lanceolate to ovate-oblong, 1.4–5.5 × 0.4–1.2 cm, base attenuate, margins entire, apex acute to rounded, surfaces glabrous or densely erect-hirsute; bracts usually very reduced, sublinear. |
Inflorescences | 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. |
leafy racemes, flowers solitary in leaf axils; bracteoles attached in subopposite pairs just proximal to ovary base, lanceolate-linear, 2.5–7 × 0.5–1.5 mm, margins entire, apex acute, surfaces hirtellous. |
Flowers | 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. |
sepals narrowly ovate-deltate, (5.4–)6–12 × 2.2–4.5(–5) mm, margins entire, apex acute, surfaces hirtellous or, sometimes, glabrous; petals cordate, 12–14 × 13–14 mm, base attenuate, apex emarginate; filaments opaque white, awl-shaped, 2–5.5 mm, anthers 1.4–2.6 × 0.4–0.8 mm; ovary subcuboid or globose, 3–4 × 3–4 mm; nectary disc elevated, domed, 1–1.4 mm diam., prominently 4-lobed, ringed with stiff, spreading hairs or glabrous; style 1.3–4.5(–5.5) mm, glabrous, stigma capitate to hemispherical, 0.9–1.5 × 0.9–2(–2.5) mm, often shallowly 4-lobed, as long as stamens, sometimes exserted beyond them. |
Capsules | subcylindric, terete or slightly angled, 5–10(–12) ×1.3–2(–2.2) mm, hard-walled, irregularly dehiscent, pedicel 0 mm. |
subcuboid to squarish globose, 4–6 × 4–5 mm, 4-angled, often also 4-winged, wings 0.3–1.1 mm wide, pedicel 3–10 mm. |
Seeds | reddish brown, oblong-elliptic, 0.6–0.7 × 0.2–0.3 mm, surface cells nearly isodiametric. |
light brown, oblong to reniform, 0.6–0.7 × 0.3–0.4 mm, surface cells elongate transversely to seed length. |
2n | = 16. |
= 16. |
Ludwigia linifolia |
Ludwigia hirtella |
|
Phenology | Flowering late Jun–Oct. | Flowering summer–early fall. |
Habitat | Drainage ditches, margins of creeks or swamps, open edges of cypress swamps, moist pinelands, edges of brackish lakes. | Boggy depressions, roadside ditches, margins of boggy streams. |
Elevation | 0–300 m. (0–1000 ft.) | 0–300 m. (0–1000 ft.) |
Distribution |
AL; FL; GA; MS; NC; SC; Mexico (Tabasco) |
AL; AR; DC; DE; FL; GA; KY; LA; MD; MS; NC; NJ; OK; SC; TN; TX; VA
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Discussion | 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.) |
A name often found in synonymy with Ludwigia hirtella is a later homonym: L. hirsuta Pursh 1813, not Desrousseaux 1789. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Isnardia linifolia | Isnardia hirsuta var. permollis, I. hirtella, L. permollis |
Name authority | Poiret in J. Lamarck et al.: Encycl., Suppl. 3: 513. (1814) | Rafinesque: Med. Repos., hexade 2, 5: 358. (1808) |
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