- Scientific Name: Ludwigia peploides subsp. stipulacea (Ohwi) P. H. Raven
- Ref: Reinwardtia. 6: 397. 1963.
- English Common Name: Water Primrose
- Chinese Common Name: 黄花水龙 huánghuā shuǐlóng
- Family: Onagraceae
- Genus: Ludwigia
- Distribution: 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].
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*. (Flora of China)