Ludwigia palustris |
Ludwigia suffruticosa |
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common water-primrose, eastern false loosestrife, ludwigie palustre, marsh primrose-willow, marsh purslane, marsh seedbox, water-purslane |
shrubby primrose-willow, shrubby primrose-willow or seedbox |
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Habit | Herbs often creeping, rooting at nodes, forming mats. | Herbs with 1–3 rhizomes 0.6–5.5 × 0.2–0.5 mm, often branched, glabrous or densely hirtellous, sometimes also forming stolons 8–80 cm, 1.1–2.2 mm thick, branched, glabrous or sparsely to densely hirtellous. |
Stems | prostrate or decumbent and ascending at tips, subterete or with raised lines decurrent from leaf axils, well branched, 10–50(–70) cm, glabrous or, sometimes, minutely strigillose on leaf margins and inflorescence. |
erect, slightly ridged, unbranched or slightly branched, (16–)30–90 cm, glabrous or strigillose to hirtellous, especially on distal parts. |
Leaves | opposite; stipules narrowly deltate, 0.05–0.1 × 0.05–0.1 mm; petiole narrowly winged, 0.1–2.5 cm, blade narrowly to broadly elliptic or ovate-elliptic, 0.5–4.5 × 0.3–2.3 cm, base abruptly attenuate, margins entire and minutely strigillose, apex subacute, surfaces glabrous; bracts not reduced. |
alternate; stipules deltate, 0.25–0.45 × 0.15–0.4 mm; rhizomes: sessile, blades minute, appressed, and scalelike, oblate or suborbiculate, 0.3–0.6 × 0.6–0.9 mm; stolons: petiole 0.1–0.6 cm, blade oblong or oblanceolate-elliptic to spatulate, 0.4–3.5 × 0.2–1.5 cm; main stem: sessile, blade lanceolate-elliptic or lanceolate-linear to linear, 2.5–9.5 × (0.1–)0.3–0.9 cm, proximal ones shorter and often oblong or oblong-lanceolate, base rounded or obtuse, margins entire with obscure hydathodal glands, apex acuminate to acute, surfaces glabrous or, sometimes, pilose on proximal blades; bracts very reduced. |
Inflorescences | leafy spikes or racemes, flowers usually paired in leaf axils of prostrate stems; bracteoles attached at base or to 2.5 mm distal to base of ovary, sublinear, 0.3–1(–1.8) × 0.1–0.8 mm. |
densely clustered, terminal racemes or spikes, 1–5(–12) cm; bracteoles attached at base of ovary or on pedicel distally, narrowly lanceolate, 3.5–5(–6) × (1.2–)1.4–2 mm, surfaces usually glabrous, sometimes pilose abaxially. |
Flowers | sepals ascending, green, ovate-deltate, 1.1–2 × 1–2.1 mm, margins finely serrulate with minute hairs, apex acuminate, sometimes with blunt tip, surfaces glabrous; petals 0; filaments translucent, 0.4–0.6 mm, anthers 0.2–0.4 × 0.3–0.6 mm; pollen shed singly; ovary oblong, 1.5–3.5 × 1–2 mm, glabrate; nectary disc elevated 0.15–0.3 mm on ovary apex, green, 1–2 mm diam., 4-lobed, glabrous; style pale green, 0.3–0.7 mm, glabrous, stigma subglobose or capitate, 0.4–0.6 × 0.2–0.4 mm, not exserted beyond anthers. |
sepals ascending, pale green or white adaxially, broadly ovate-deltate, 2.3–3.5(–4) × 2.3–3.2(–3.8) mm, margins entire, apex acuminate, surfaces glabrous; petals 0; filaments yellow or cream, 1.2–2 mm, distinctly dilated toward base, anthers 0.7–1(–1.3) × 0.5–0.7 mm; pollen shed in tetrads; ovary broadly obovoid or cup-shaped, 2.2–3 × 2.3–3.3 mm; nectary disc elevated 0.5–0.6 mm on ovary apex, pale yellow, 1.8–3.1 mm diam., obscurely 4-lobed, glabrous; style pale yellow, 0.9–1.7 mm, glabrous, stigma pale green to white, globose to capitate, 0.4–0.8 × 0.5–0.8 mm, distinctly 4-lobed, not exserted beyond anthers. |
Capsules | oblong obovoid, 4-angled, (1.6–)2–5 × 1.5–3(–3.5) mm, thin-walled, irregularly dehiscent or dispersing as unit, pedicel 0–0.5 mm. |
broadly obpyramidal, angles rounded, sometimes subspherical, 2.5–4.3 ×2.5–4.5(–5) mm, hard-walled, dehiscent by apical ring, pedicel 0.5–1.5(–2) mm. |
Seeds | yellowish brown, ellipsoid, 0.5–0.7 × 0.3–0.4 mm, surface cells transversely elongate. |
brown, elliptic-oblong, curved on both ends, 0.5–0.6 × 0.2–0.3 mm, surface cells ± isodiametric. |
2n | = 16. |
= 32. |
Ludwigia palustris |
Ludwigia suffruticosa |
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Phenology | Flowering Feb–Oct. | Flowering May–Sep. |
Habitat | Roadside ditches, wet meadows, dried pond bottoms, margins of ponds, swamps, rivers, alluvial sand bars. | Sandy ditches, marshes, wet meadows, limestone sinks, cypress swamps, moist pinelands. |
Elevation | 0–1000[–2700] m. (0–3300[–8900] ft.) | 0–150 m. (0–500 ft.) |
Distribution |
AL; AR; AZ; CA; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; BC; NB; NF; NS; ON; QC; Mexico (Chiapas, Chihuahua, Guerrero, Hidalgo, Jalisco, México, Michoacán, Morelos, Nuevo León, Oaxaca, San Luis Potosí, Sinaloa, Sonora, Tamaulipas, Veracruz); West Indies (Cuba, Hispaniola, Jamaica, Puerto Rico); Bermuda; Central America (Costa Rica, Guatemala, Panama); South America (Colombia, Peru, Venezuela); Europe; sw Asia; Africa; introduced in Pacific Islands (Hawaii, New Zealand); Australia
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AL; FL; GA; NC; SC
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Discussion | Ludwigia palustris is a common diploid and most widely distributed species in sect. Isnardia. It is particularly widespread in temperate North America and in Europe [the type is thought to be from Europe (P. H. Raven 1963[1964]; C. I. Peng et al. 2005)], more sporadically in Africa and sw Asia, and introduced in Australasia, and Hawaii. The close sister relationship of sect. Isnardia with sect. Miquelia (L. ovalis Miquel only, endemic to eastern Asia) suggests that this clade may have had a history connected with the evolution of the Arcto-Tertiary Geoflora (P. H. Raven and D. I. Axelrod 1974; Peng et al.). Ludwigia palustris is known to hybridize with L. brevipes producing the sterile L. ×lacustris Eames. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Ludwigia suffruticosa is distinctive by virtue of its highly condensed inflorescence and sessile leaves. It also differs from other species in sect. Isnardia in that it perennates mainly by underground rhizomes. This apetalous species has showy bracts and attracts many insects, including bumblebees, wasps, and honeybees (C. I. Peng 1989). Its center of distribution is in Florida, extending along the coastal plain barely to Alabama on the west and barely to southern North Carolina on the northeast. Recent reports of this species from Mississippi and from Mexico (Chiapas and Oaxaca) have not been confirmed. (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. Isnardia |
Sibling taxa | ||
Synonyms | Isnardia palustris, I. ascendens, I. nitida, I. palustris var. americana, L. apetala, L. nitida, L. palustris var. americana, L. palustris var. inundata, L. palustris var. liebmannii, L. palustris var. nana, L. palustris var. pacifica | Isnardia suffruticosa |
Name authority | (Linnaeus) Elliott: Sketch Bot. S. Carolina 1: 211. (1817) | Walter: Fl. Carol., 90. (1788) |
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