Two new species and

Two new species, Exobasidium rhododendri-nivalis on Rhododendron nivale and E. pyroloides on Gaultheria pyroloides, are reported. They were collected from Yunnan and Sichuan Provinces. Exobasidium rhododendri-nivalis causes small galls on leaves, stems and shoots, while E. pyroloides causes red leaf spots. Exobasidium cylindrosporum on Rhododendron sp., collected from Jiangxi Province, is reported as new to China. Key words—Ustilaginomycetes, symptoms, taxonomy Two new species of Exobasidium, collected from southwestern China, are described and illustrated. The first new species was collected in 2007 from Yunnan and Sichuan Provinces at altitudes of 4300 m and 4650 m. It is parasitic on Rhododendron nivale (subfamily Rhododendroideae of Ericaceae), causing small galls measuring 1–4 mm in diam. on leaves, stems and shoots. On leaves there are 1–5 (or more) galls on the lower surface. Diseased leaves are convex on the upper surface. The galls are red when fresh and become pale yellowish brown to black when old. Basidiospores with short germ tubes were observed in some microscopical slides of fresh material. The new species is described as: Exobasidium rhododendri-nivalis ZhenYing Li & L. Guo, sp. nov. Figs. 1, 4-7 MycoBank MB 511910 Hymenium album. Basidia clavata vel cylindrica, 7–18 × 4–8 μm, hyalina, terminaliter 2–4 sterigmatibus 4.5–7 × 1–1.5 μm praedita. Basidiosporae ellipsoideae, curvae, 10.2–13 × 2.5–3 μm, hyalinae, laeves, primo continuae, dein 1-septatae; per hyphas germinantes.