3. Diabelia Landrein, Phytotaxa. 3: 35. 2010.
双六道木属 shuang liu dao mu shu
Linnaea [unranked] Serratae Graebner, Bot. Jahrb. Syst. 29: 127. 1900.
Shrubs, deciduous. Winter buds exposed, with several pairs of scales. Branches without grooves. Leaves opposite, shortly petiolate with an interpetiolar line, estipulate. Leaf margin entire to serrate, often undulate. Flowers terminal and paired at ends of short shoots (flowers opening simultaneously); flowers sometimes 1-3(-8) due to supernumerary flowers axillary to bracteoles (more often so on repeat-bloom long shoots); paired flowers with 6 bracts at base of ovaries, bracts small and not accrescent. Sepals 2-5, spreading, narrowly oblong, elliptic, persistent and ± accrescent in fruit. Corolla 5-lobed, bilabiate, white, yellow, pink, or red. Corolla tube gibbous ventrally at base and containing a nectary of dense glandular hairs sometimes clavate and free (nectaria trichomalia). Stamens didynamous, adnate to corolla tube, included or exserted; anthers introrse. Ovary narrowly oblong, 3-locular, 2 locules with 2 series of sterile ovules, 1 locule with a single fertile ovule; style filiform; stigmas capitate, white and papillose. Fruit an oblong, leathery achene, crowned with persistent sepals. Seed subterete, testa membranous; endosperm fleshy.
Three species: China, Japan; two species in China.
