Yellow Floatingheart

Limnanthemum cordatum Dunn, described from a specimen collected in NE Guangdong, is probably synonymous with Nymphoides peltata.

Rhizomes horizontal. Stem cylindric, unbranched, sometimes producing rootlets from nodes. Leaves alternate at stem base but opposite at apex; petiole cylindric, 5-10 cm, base widened into an amplexicaul sheath; leaf blade ovate-orbicular to orbicular, 1.5-8 cm in diam., subcoriaceous, abaxially purple-brown and densely glandular, adaxially glabrous, base cordate, margin entire, veins indistinct. Flowers usually densely clustered at nodes, 5-merous, distylous. Pedicel 3-7 cm. Calyx 7-9 mm, lobed to near base; lobes elliptic-lanceolate to elliptic, apex obtuse. Corolla golden yellow, 2.5-3 cm, rotate, lobed to near base; lobes obovate, margin broadly membranous and irregularly laciniate, apex rounded to emarginate. Filaments sparsely pilose. Short styled flowers: ovary 5-7 mm; style 1-2 mm; stigma small, filaments 3-4 mm; anthers curved, sagittate, 4-6 mm. Long styled flowers: ovary 0.7-1.7 cm; style to 1 cm; stigma large, 2lobed, suborbicular; filaments 1-2 mm; anthers 2-3.5 mm. Glands golden yellow. Capsules elliptic, 1.7-2.5 × 0.8-1.1 cm. Seeds brown, compressed, elliptic, 4-5 mm, densely ciliate. Fl. and fr. Apr-Oct. 2n = 54.

Essentially throughout China except Hainan, Qinghai, and Xizang [Japan, Korea, Mongolia, Russia; C and SW Asia, Europe]

Standing water; below 100-1800 m.

Limnanthemum peltatum S. G. Gmelin, Novi Comment. Acad. Sci. Imp. Petrop. 14(1): 527. 1770; Menyanthes nymphoides Linnaeus.