Citrus junos Sieb. ex Tanaka

The parents of this hybrid species are possibly Citrus cavaleriei and C. reticulata.

Small trees. Branches often with long stout spines; branchlets, leaves, and petioles sparsely pubescent when young. Petiole obovate-elliptic, 1-2.5 × 0.4-1.5 cm, base cuneate, apex rounded to obtuse; leaf blade ovate to lanceolate, 2.5-8 × 1-4 cm, thickly papery, base rounded to obtuse, margin apically finely dentate or rarely entire, apex acuminate, mucronate, or often obtuse and emarginate. Flowers solitary, shortly pedicellate. Calyx cup-shaped; lobes 4 or 5, broadly ovate, apex acute. Petals white, sometimes outside purplish, 1-1.3 cm. Stamens 20-25. Style ca. 2 × as long as ovary. Fruit pale yellow, oblate to nearly pyriform, 4-8 cm in diam., surface coarse and with large oil dots, apex grooved; pericarp 2-4 mm thick, easily removed; sarcocarp with 9-11 segments, pale yellowish white, very acidic and bitter. Seeds ca. 40, broadly ovoid, smooth; cotyledons milky white; embryo(s) solitary to numerous. Fl. Apr-May, fr. Oct-Nov.

Cultivated and sometimes naturalized. S Anhui, S Gansu, Guizhou, Hubei, Hunan, S Jiangsu, S Shaanxi, Sichuan, Yunnan, Zhejiang.

Citrus ×aurantium Linnaeus subsp. junos (Siebold ex Tanaka) Makino; C. ×hsiangyuan Tanaka; C. medica subf. junos (Siebold ex Tanaka) Hiroe; ?C. sechen Kokaya; C. sechen subsp. sjanshen Kokaya; ?C. ×wilsonii Tanaka.