- Scientific Name: Gentiana yokusai Burkill
- Ref: J. & Proc. Asiat. Soc. Bengal. 2: 316. 1906.
- Synonyms: Gentiana agrorum Harry Smith;
G. tenuissima Hayata;
G. yokusai var. japonica Burkill.
- Chinese Common Name: 灰绿龙胆 hui lu long dan
- Family: Gentianaceae
- Genus: Gentiana
- Distribution: 0-2700 m. Anhui, Fujian, Guizhou, Hebei, Hubei, Hunan, Jiangsu, Jiangxi, Nei Mongol, Shaanxi, Shanxi, Sichuan, Taiwan, Zhejiang [Japan, Korea]
- Type: In provincia Kwang-tung, sine loco indicato, Wenyon: in provincia Kiangsu ad oppidum Shanghai, Maingay 424: in provincia Kiangsi ad Kewkiang, Shearer: in provincia Hupeh, sine loco indicato, Henry 7377; ad Ichang, Henry 506; ad Chienshi, Wilson 561: in provincia Szechuen, sine loco indicato, Henry 8858; ad Liu-hua-tsao, Chung-ching, Bourne s.n.; ad oppidum Tachienlu, Pratt, 388; in ripis fuminium Yang-tze-kiang et Min, Faber 295
Annuals 2.5-14 cm tall. Stems ascending to erect, branched throughout, usually with 2-5 crowded flowering branches, densely papillate. Petiole 1.5-2.5 mm, margin ciliolate; leaf blade adaxially sometimes densely and minutely papillate, base obtuse, margin thick cartilaginous, apex acuminate and with an aristate tip to 0.7 mm, midvein prominent. Basal leaf blades lanceolate to ovate-lanceolate, 0.7-2.2 cm × 4.5-8 mm. Stem leaves spreading; leaf blade ovate or cordate, 4-12 × 3-6 mm. Pedicel 1.2-1.5 mm, papillate. Calyx narrowly obconic, 5-8 mm; lobes slightly spreading, lanceolate to ovate, 2-3 mm, slightly unequal, base slightly narrowed, margin thick cartilaginous and ciliolate, apex acuminate and with an aristate tip to 0.7 mm, midvein prominent. Corolla blue to blue-purple, funnelform, 7-12 mm; lobes ovate, 2-2.5 mm, margin entire, apex obtuse; plicae ovate, 1-1.5 mm, margin entire or denticulate, apex obtuse. Stamens inserted just below middle of corolla tube, equal; filaments 2-2.5 mm; anthers narrowly ellipsoid, 0.5-0.8 mm. Style 1.5-2 mm; stigma lobes linear. Capsules narrowly obovoid to obovoid, 3-6.5 mm; gynophore to 1.3 cm, stout. Seeds light brown, oblong to ellipsoid, 0.7-1 mm. Fl. and fr. Mar-Sep.(Flora of China)
