Description from Flora of China
Utricularia confervifolia Jackson ex D. Don; U. extensa Hance; U. fasciculata Roxburgh; U. flexuosa Vahl; U. pilosa (Makino) Makino; U. vulgaris Linnaeus var. pilosa Makino.
Perennials or annuals, suspended aquatic. Rhizoids usually present, verticillate at base or shortly above base of peduncle, fusiform, inflated, with filiform branches. Stolons filiform to relatively thick, branched. Traps on leaf segments, stalked, obliquely ovoid, 1-4 mm, mouth lateral or basal; appendages 2 or sometimes absent, dorsal, sparsely branched, setiform. Leaves numerous on stolons, 2-8 cm, divided from base into 3 or 4(or 5) semiverticillate primary segments; primary segments ovate to oblong-lanceolate in outline, 1.5-3 cm wide, pinnately divided into secondary segments; secondary segments dichotomously divided from base into numerous further segments; ultimate segments capillary, slightly flattened, laterally and apically setulose; stipulelike auricles usually present at base of primary segments, semicircular in outline, divided dichotomously into filiform sparsely setulose segments. Inflorescences erect, 5-25 cm, 3-10-flowered, glabrous; peduncle terete, 0.5-1.5 mm thick; scales absent; bracts basifixed, broadly ovate to orbicular, 1-2 mm, apex rounded. Pedicel erect at anthesis but sharply deflexed and thickened in fruit, 0.4-2 cm, dorsiventrally compressed; bracteoles absent. Calyx lobes ovate, subequal, apex rounded to subacute; lower lobe often slightly broader than upper lobe, 2-3 mm at anthesis, becoming fleshy, 7-9 mm, and spreading to reflexed in fruit. Corolla pale yellow, 1-1.5 cm, pubescent or glabrous; lower lip transversely elliptic, base with a prominent 2-lobed swelling, apex rounded to emarginate; spur cylindric from a narrowly conic base, ± as long as and parallel with lower lip, straight or slightly curved, apex obtuse to subacute; palate pubescent; upper lip broadly ovate, apex rounded. Filaments 1-1.5 mm, curved; anther thecae ± confluent. Ovary ovoid; style evident; stigma lower lip semicircular, upper lip obsolete. Capsule globose, 4-5 mm in diam., circumscissile; persistent style greatly enlarged and elongated, often equaling or exceeding capsule. Seeds prismatic, 1-2 mm wide, 5- or 6-angled, narrowly winged on all angles; seed coat with ± isodiametric obscure reticulations. Fl. Jun-Nov, fr. Jul-Dec. 2n = 80.
Pools, lakes, swamps, river backwaters, rice fields; near sea level to 2700 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Shandong, Taiwan, Yunnan, Zhejiang [Cambodia, India, Indonesia, Japan, Kashmir, Korea, Laos, Nepal, Pakistan, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Australia].