Ludwigia hexapetala |
Ludwigia bonariensis |
|
---|---|---|
false loosestrife, large-flower primrose-willow, primrose willow, six petal water primrose, Uruguayan primrose-willow, water primrose |
Carolina primrose-willow |
|
Habit | Herbs, subshrubs, or emergent aquatics, adventitious roots sometimes forming a thick mass 10–23 cm at submerged nodes, sometimes woody at base, white pneumatophores 5–10 cm often on submerged stems. | Herbs, from woody rootstock. |
Stems | floating or creeping and ascending to erect, terete, 20–200(–400) cm, simple to densely branched apically, glabrous (floating) or sparsely to densely villous (emergent), sometimes villous only on inflorescence. |
erect, subterete, 20–120 cm, branched, glabrate proximally, or strigillose, especially in distal parts, with raised strigillose lines decurrent from leaf axils mid stem. |
Leaves | stipules ovate or deltate, 0.7–2 × 0.5–1.1 mm, not succulent, apex subacute, mucronate; petiole flattened, 0.5–2(–2.5) cm; blade narrowly oblanceolate, narrowly elliptic, or lanceolate to obovate or spatulate, (1.5–)4.2–10.7(–13.5) × (0.5–)0.8–3 cm, chartaceous, base cuneate or attenuate, margins entire, apex acute to obtuse, rounded or truncate, sometimes mucronate, surfaces not shiny, usually glabrous, sometimes villous on petiole and veins or throughout; bracts not reduced. |
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. |
Inflorescences | emergent stems sometimes in leafy racemes, sometimes reflexed, flowers solitary in leaf axils; bracteoles obovate to narrowly obovate, 1–1.8 × 0.7–0.8 mm, apex acute or acuminate, attached on distal 1/2 of pedicel or at ovary base. |
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. |
Flowers | sepals ovate-deltate or lanceolate-deltate, (8–)12–19 × 2–5 mm, chartaceous, margins entire, apex acuminate, surfaces ± densely villous; petals bright yellow, sometimes with orange base, fan-shaped, (15–)20–30 × (12–)16–25 mm, apex emarginate or mucronate; stamens 10(or 12), in 2 unequal series, yellow, filaments recurved, shorter ones (1.6–)2.3–5.2 mm, longer ones (3.1–)3.6–7.5 mm, anthers oblong, (1.2–)1.7–4 × 1–1.5 mm; ovary subcylindric, terete, 10–18 × 2–3 mm, apex ± broadened, glabrous or sparsely to densely villous; nectary disc slightly raised on ovary apex, yellowish green, 2–4 mm diam., lobed, glabrous or ringed with white hairs; style yellow, 6–10 mm, glabrous, stigma subcapitate-globose, 0.5–1.5 × 1.5–2.5 mm, often exserted beyond anthers. |
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. |
Capsules | cylindric or subclavate, terete, sometimes curved, (12–)16–24(–30)× 2.5–4 mm, with thick woody walls, irregularly and tardily dehiscent, pedicel (9–)13–25(–85) mm. |
clavate-cylindric, subterete to obtusely 4-angled, 20–35 × 3.5–5 mm, thin walls, irregularly dehiscent, tapering to pedicel 10–40 mm. |
Seeds | embedded in wedge-shaped piece of endocarp, 0.8–1 × 0.8–1 mm. |
in several indistinct rows per locule, yellow-brown, oblong (appearing round), 0.5 mm, shiny, raphe 2/3 as wide as body. |
2n | = 80. |
= 16. |
Ludwigia hexapetala |
Ludwigia bonariensis |
|
Phenology | Flowering spring–late fall. | Flowering summer. |
Habitat | Wet places, along slow-moving rivers, streams, canals, ditches, often growing into main channel as aquatic weed. | Wet places, mainly along coastal areas, especially ditches, banks near brackish water. |
Elevation | 0–200[–2600] m. (0–700[–8500] ft.) | 0–200[–2600] m. (0–700[–8500] ft.) |
Distribution |
AL; AR; CA; FL; GA; KY; LA; MS; NC; NY; OR; PA; SC; TN; WA; Central America (Costa Rica); South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Paraguay, Peru, Uruguay) [Introduced in w Europe (Belgium, France, Spain)]
|
AL; FL; MS; NC; SC; TX; Mexico (Chihuahua, Durango, Puebla, Quintana Roo, Tabasco, Tamaulipas, Veracruz); South America (Argentina, Bolivia, Brazil, Paraguay, Uruguay)
|
Discussion | Ludwigia hexapetala (2n = 80) was formerly included with L. grandiflora (2n = 48) in L. uruguayensis (Cambessèdes) H. Hara, and some authors (G. L. Nesom and J. T. Kartesz 2000) still consider them to be a single species. The small but consistent morphological differences and different ploidy levels argue for keeping them distinct at the species level. Fernald described Jussiaea michauxiana (1944), since he thought that J. grandiflora Michaux (1803) was a homonym (not J. grandiflora Ruíz & Pavon). However, it was later determined that the volume containing the Ruíz & Pavon name was published in 1830 (not 1802) making the name by Michaux valid and legitimate, and the name by Fernald an illegitimate substitution. Plants now known as Ludwigia hexapetala were included in the circumscription of L. uruguayensis (Cambessèdes) H. Hara (based on J. uruguayensis Cambessèdes) by P. H. Raven (1963[1964]) and P. A. Munz (1965). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Jussiaea | Onagraceae > subfam. Ludwigioideae > Ludwigia > sect. Macrocarpon |
Sibling taxa | ||
Synonyms | Jussiaeahexapetala hooker, J. repens var. major, L. grandiflora subsp. hexapetala, L. grandiflora var. hexapetala, L. uruguayensis var. major | Jussiaea bonariensis, J. neglecta, J. suffruticosa var. bonariensis |
Name authority | (Hooker & Arnott) Zardini, H. Y. Gu & P. H. Raven: Syst. Bot. 16: 243. (1991) | (Micheli) H. Hara: J. Jap. Bot. 28: 291. (1953) |
Web links |
|