Ludwigia maritima |
Ludwigia ravenii |
|
---|---|---|
seaside primrose-willow |
Raven's primrose-willow |
|
Habit | Herbs slender, rarely with aerenchyma when base submerged, forming slender, glabrate stolons 10–18 cm, 0.6–1.5 mm thick, occasionally bearing flowers and fruits. | |
Roots | fibrous or fusiform, sometimes fascicled. |
|
Stems | subterete to scarcely angled, with narrow raised lines or wings decurrent from leaf axils, 30–90 cm, simple or sparsely branched distally, strigillose to sometimes glabrate. |
erect, slightly ridged, usually well branched, (15–)35–90 cm, densely hirtellous. |
Leaves | stipules narrowly deltate, 0.05–0.2 × 0.05–0.1 mm; sessile; blade ovate proximally, lanceolate to lanceolate-linear distally, (2–)3–8 × 0.3–1.5 cm, base cuneate, margins entire, apex acute, surfaces glabrate to strigillose or hirsute; bracts usually much reduced, sublinear. |
alternate; stipules lanceolate to broadly deltate, 0.2–0.5 × 0.1–0.3 mm; stolons: petiole 0.1–0.3 cm, blade elliptic to orbiculate, 1–1.8 × 0.6–1.4 cm, base attenuate, apex rounded to acute; stems: petiole narrowly winged, 0.1–0.8 cm, blade narrowly lanceolate-elliptic, 1.3–6.5 × 0.4–1.5 cm, base attenuate, margins entire with minute hydathodal glands, apex acute, surfaces densely hirtellous; bracts not much reduced. |
Inflorescences | sparse racemes, flowers solitary in leaf axils; bracteoles attached in subopposite pairs on distal 1/3 of pedicel, lanceolate-linear, 0.7–3.2(–5) × 0.2–0.5 mm, margins entire, apex acute, surfaces strigillose. |
leafy racemes, flowers solitary in leaf axils; bracteoles attached near base of ovary, lanceolate or elliptic to narrowly so, (1.5–)2–4.3 ×0.3–0.9 mm, apex acuminate, surfaces hirtellous. |
Flowers | sepals often spreading, ovate-deltate, (4.5–)5.5–8(–9) × 3–5 mm, margins entire, apex acute to obtuse, surfaces strigillose; petals cordate, 9–12 × 8–10 mm, base attenuate, apex emarginate; filaments yellow, awl-shaped, 1.9–3.2 mm, anthers 1.2–2.5 × 0.4–0.7 mm; ovary subcuboid or globose, 3–4.5 × 3–4 mm; nectary disc elevated, domed, 0.9–1.3 mm diam., prominently 4-lobed, ringed with sparse, spreading hairs; style 1.5–3.3 mm, glabrous, stigma capitate to hemispherical, 0.6–1.2 × 1.4–1.9 mm, shallowly 4-lobed, not exserted beyond anthers. |
sepals ascending-spreading, green, broadly ovate-deltate, 1.5–3 × 1.4–2.1 mm, margins entire, apex acuminate, surfaces densely hirtellous; petals 0; filaments light green, 0.7–1.1 mm, anthers 0.3–0.4 × 0.4–0.5 mm; pollen shed in tetrads; ovary obovoid to obconic, 2.8–3.5 × 2–3 mm; nectary disc elevated 0.3–0.4 mm on ovary apex, light green, 1.4–2.5 mm diam., 4-lobed, glabrous; style light green, 0.3–0.5 mm, glabrous, stigma clavate to subcapitate, 0.4–0.6 × 0.3–0.5 mm, not exserted beyond anthers. |
Capsules | subcuboid to squarish globose, 4–7 ×4–5 mm, 4-angled, often also 4-winged, wings 0.3–1.2 mm wide, pedicel 5–17 mm. |
oblong-obovoid, subterete to scarcely 4-angled, (3–)4–5(–5.3) × 2.5–3.5(–4) mm, hard-walled, irregularly dehiscent, pedicel 0.2–0.5 mm. |
Seeds | light brown, oblong to reniform, 0.4–0.6 ×0.2–0.4 mm, surface cells elongate transversely to seed length, except may be parallel to seed length near raphe. |
light brown, elliptic-oblong with slightly curved ends, 0.5–0.7 ×0.3–0.4 mm, surface cells elongate transversely to seed length. |
2n | = 16. |
= 32. |
Ludwigia maritima |
Ludwigia ravenii |
|
Phenology | Flowering summer. | Flowering Jul–Sep. |
Habitat | Damp, sandy, or peaty habitats, roadside ditches, margins of bogs or fields, usually within 75 miles of sea coast. | Wet, peaty habitats, ditches, margins of ponds, bogs, swamps. |
Elevation | 0–200 m. (0–700 ft.) | 0–100 m. (0–300 ft.) |
Distribution |
AL; FL; GA; LA; MS; NC; SC
|
FL; NC; SC; VA |
Discussion | Ludwigia ravenii is an uncommon species occurring in scattered populations in coastal southeastern Virginia and eastern North Carolina, with single disjunct populations in southeastern South Carolina and northeastern Florida. C. I. Peng (1989) observed its similarity to L. pilosa by virtue of its dense, hirtellous pubescence, but noted its smaller, more consistently autogamous flowers. It is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Ludwigia | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Isnardia |
Sibling taxa | ||
Name authority | R. M. Harper: Torreya 4: 163, fig. 2. (1904) | C. I. Peng: Syst. Bot. 9: 129, fig. 1. (1984) |
Web links |