205. Gentiana leucomelaena Maximowicz ex Kusnezow, Bull. Acad. Imp. Sci. Saint-Pétersbourg. 34: 505. 1892.
蓝白龙胆 lan bai long dan
Gentiana humilis Steven var. evolutior C. B. Clarke; G. leucomelaena var. alba Kusnezow; G. leucomelaena var. pusilla Krylov.
Annuals 2-10 cm tall. Stems prostrate to ascending, branched from base, glabrous. Basal leaves withered at anthesis; petiole 1-2 mm; leaf blade ovate-elliptic to ovate-orbicular, 5-8 × 2-3 mm, margin indistinctly membranous, apex obtuse to rounded; veins 1-3, indistinct. Stem leaves 3-5 pairs; petiole tube 1.5-3 mm; leaf blade lanceolate to elliptic, rarely basally spatulate to ovate, 3-9 × 0.7-2 mm, usually shorter than internodes, margin narrowly and indistinctly membranous, apex acuminate to obtuse, midvein abaxially distinct. Flowers few. Pedicel 0.4-4 cm, glabrous. Calyx campanulate, 4-5 mm; lobes triangular, 1.5-2 mm, margin narrowly membranous, apex acute, midvein indistinct. Corolla pale blue, rarely white, with blue-gray stripes, with dark blue spots in throat, campanulate, 0.8-1.3 cm; lobes ovate, 2.5-3 mm, margin entire, apex obtuse; plicae oblong, 1.2-1.5 mm, margin irregularly laciniate, apex obtuse. Stamens inserted at basal part of corolla tube, equal; filaments 2.5-3.5 mm; anthers ellipsoid, 0.7-1 mm. Style 0.5-0.7 mm; stigma lobes oblong. Capsules obovoid, 3.5-5 mm; gynophore to 2 cm, stout. Seeds broadly dark brown, ellipsoid, 0.6-0.8 mm. Fl. and fr. May-Oct.
Along streams, bog meadows, meadows, alpine meadows, scrub; 1900-5000 m. Gansu, Qinghai, Sichuan, Xinjiang, Xizang [Kashmir, Kazakhstan, Kyrgyzstan, N Mongolia, Nepal, Pakistan, Russia, Sikkim, Tajikistan]
The widespread Gentiana leucomelaena is similar to the much more narrowly distributed G. aperta. Although T. N. Ho treats them as distinct species, J. S. Pringle considers G. leucomelaena as a synonym of G. aperta.