7. Ludwigia peploides (Kunth) P. H. Raven subsp. stipulacea (Ohwi) P. H. Raven, Reinwardtia. 6: 397. 1963.
黄花水龙 huang hua shui long
Jussiaea stipulacea Ohwi, J. Jap. Bot. 26: 232. 1951; Ludwigia adscendens (Linnaeus) H. Hara var. stipulacea (Ohwi) H. Hara; L. stipulacea (Ohwi) Ohwi.
Herbs perennial, sprawling and rooting at nodes or floating, pneumatophores usually absent on floating stems but sometimes present on stems under water. Floating stems to 300 cm, terrestrial stems 10-60 cm, branched, ascending, glabrous. Petiole 2-35 mm; leaf blade oblong, 2.5-10 × 1-3.2 cm, lateral veins 7-11 per side, submarginal vein not prominent, base narrowly cuneate, apex acute or acuminate. Sepals 5, deltoid-acuminate, 6-12 mm, glabrous or villous. Petals bright golden-yellow with a darker spot at base, obovate, 9-17 × 5-11 mm. Stamens 10; filaments bright yellow, 2.5-5 mm; anthers pale yellow, 1-1.8 mm; pollen in monads. Style yellow, 2.5-5 mm, lower half densely long hairy; stigma depressed-globose, deeply 5-lobed. Capsule light brown, cylindric, somewhat 5-angled, abruptly narrowed at base, scarcely narrowed at apex, 1.2-4 cm, 2-5 mm in diam., glabrous, thickly walled, tardily and irregularly dehiscent; pedicels 2-6.5 cm. Seeds in one row per locule, firmly embedded in coherent cubes of woody endocarp fused to capsule wall, pale brown, 1.1-1.3 mm, raphe inconspicuous. Fl. May-Oct, fr. Jul-Nov. 2n = 16*.
Wet swampy areas, especially along rivers, ditches, and lakes, often in disturbed and/or cultivated areas; near sea level to 300 m. Anhui, Fujian, Guangdong, Zhejiang [Japan].
Ludwigia peploides subsp. peploides is native to the S United States through W and C South America to Argentina, and is intro duced on some Pacific islands. Ludwigia peploides subsp. montevidensis (Sprengel) P. H. Raven is native to S Brazil, Uruguay, Argentina, and Chile, and is introduced in the United States (California), as well as in France, Australia, and New Zealand.