3. Utricularia caerulea Linnaeus, Sp. Pl. 1: 18. 1753.
短梗挖耳草 duan geng wa er cao
Calpidisca tatenakae Nakai; Utricularia albiflora Griffith (1854), not R. Brown (1810); U. albina Ridley; U. caerulea var. filicaulis (Wallich ex A. Candolle) Haines; U. capillaris D. Don; U. cavaleriei Stapf; U. filicaulis Wallich ex A. Candolle; U. filicaulis var. papillosa Pellegrin; U. kerrii Craib; U. nivea Vahl; U. obtusiloba Benjamin; U. ophirensis Ridley; U. racemosa Wallich ex Walpers; U. racemosa var. filicaulis (Wallich ex A. Candolle) C. B. Clarke; U. rosea Edgeworth; U. roseopurpurea Stapf ex Gamble; U. sampathii Subramanyam & Yoganarasimhan; U. sootepensis Craib; U. squamosa Benjamin.
Annuals, terrestrial. Rhizoids and stolons capillary, branched. Traps on stolons and leaves, stalked, ovoid, 0.2-1 mm, with stipitate glands on appendage and mouth margin, mouth lateral; appendage 1, dorsal, subulate, beaklike. Leaves numerous, from peduncle base and stolon nodes, glabrous; leaf blade linear to linear-obovate, 0.3-2 cm × 0.5-2 mm, membranous, veins 3, base attenuate onto petiole, margin entire, apex rounded. Inflorescences erect, 5-44 cm, 1-15-flowered, glabrous; peduncle terete, 0.3-1.2 mm thick; scales 1-12, similar to bracts; bracts basisolute, oblanceolate, 1.5-3 mm, base cuneate, apex acute. Pedicel erect at anthesis but spreading to deflexed in fruit, 0.2-1 mm, minutely papillose; bracteoles basisolute, ovate-lanceolate, 1-2 mm. Calyx lobes minutely papillose, glabrous; lower lobe suborbicular, smaller than upper lobe, apex retuse; upper lobe ovate-oblong, 2-3 mm, apex rounded. Corolla violet, pink, or white, marked with yellow at throat, 4-10 mm; lower lip broadly ovate, with a basal 4-ridged swelling, apex rounded to emarginate; spur narrowly conic, usually longer than lower corolla lip, apex subacute; upper lip oblong to ovate-oblong, apex retuse. Filaments 1-2 mm, straight; anther thecae ± distinct. Ovary globose; style short; stigma lower lip semicircular, upper lip deltoid. Capsule globose to ellipsoid, 1.5-2 mm, dehiscing by a short longitudinal ventral slit. Seeds obovoid to oblong-ellipsoid, 0.2-0.3 mm; seed coat with prominent elongate reticulations and conic to clavate papillae. Fl. Jun-Jan, fr. Jul-Feb. 2n = 36, 40.
Wet rocks, beside streams, wet grassland, swamps, damp places; near sea level to 2000 m. S Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Shandong, Taiwan, Yunnan [Bangladesh, Cambodia, India, Indonesia, Japan, Korea, Laos, Malaysia, Myanmar, Nepal, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Australia, Madagascar, Pacific islands (Guam, Palau)].
Reports of Utricularia caerulea from Anhui, Jiangsu, Jiangxi, Sichuan, and Zhejiang (Z. Yu Li, FRPS 69: 594. 1990; S. R. Chen, Higher Pl. China 10: 440. 2004) are in fact U. warburgii.