Description from Flora of China
Utricularia fluitans Ridley.
Perennials, freely suspended aquatic. Rhizoids apparently absent. Stolons filiform, branched. Traps on leaves, shortly stalked, broadly obliquely ovoid, 1-2 mm, mouth lateral; appendages 2, dorsal, branched, setiform, with simple shorter setae. Leaves numerous on stolons, 2-6 cm, divided from near base into 2 or 3 primary segments; segments elliptic in outline, dichotomously divided into numerous further segments; ultimate segments capillary, terete, sparsely minutely setulose. Inflorescences erect, 6-20 cm, 5-10-flowered; peduncle terete, 0.6-1 mm thick, glabrous; scales few, similar to bracts; bracts basisolute, ovate, 2-2.5 mm, glandular. Pedicel erect, 3-10 mm, filiform, slightly dorsiventrally compressed; bracteoles absent. Calyx lobes orbicular, convex, 1-1.8 mm; lower lobe slightly smaller, apex truncate to retuse; upper lobe apex rounded. Corolla lilac, violet, or white, with a yellow blotch at base of lower lip, 6-10 mm; lower lip transversely oblong-elliptic to subreniform, base with prominent 2-lobed swelling, apex rounded to retuse; spur narrowly conic, ± as long as and parallel with lower lip, slightly curved, apex truncate to emarginate; palate margin glabrous; upper lip transversely elliptic, cucullate, apex rounded. Filaments ca. 1.5 mm, curved; anther thecae confluent. Ovary broadly ovoid; style evident, glandular; stigma lower lip transversely elliptic, upper lip semicircular to deltoid. Capsule ellipsoid, ca. 3 mm, dehiscing by longitudinal dorsal and ventral slits. Seed few per capsule, lenticular, ca. 2 mm in diam., margin broadly winged, wing irregularly dentate; seed coat with small prominent reticulations. Fl. Jun-Aug, fr. Jul-Sep.
Lakes, swamps, rice fields; near sea level. S Fujian (Longhai), S Guangxi (Dongxing) [Indonesia, Malaysia, Myanmar, Thailand, Vietnam].