Phyllosticta hostae Y.Y. Su & L. Cai, Persoonia 28: 79 (2012).

MycoBank number: MB 564904; Index Fungorum number: IF 564904; Facesoffungi number: FoF 07380; Fig. 19

Leaf spots circular to somewhat irregularly rotundate, pale brown to brown. Sexual morph: Undetermined. Asexual morph: Colonies on PDA, Pycnidia black, sub epidermal, globose, 40–150 µm in diam. dark brown to black, darker around ostiole. Conidiogenous cells holoblastic, phialidic, cylindrical, subcylindrical to ampulliform, hyaline, thin-walled, smooth. Conidia 8–15 × 5–9 µm (= 10 × 7, n = 20), unicellular, thin- and smooth-walled, ellipsoid, subglobose to obovoid, with large central guttule, truncate at the base when young, later rounded at both ends, enclosed in a 1–3 µm thick mucilaginous sheath, and bearing a hyaline, mucoid apical appendage, 4–8 × 1–3 µm, straight to flexuous, unbranched, tapering towards an acute tip.

Material examined: China, Beijing Tongzhou-Yongle Eco Park, leaf spot on rose (Rosaceae) leaves, 18 August 2018, Jia Jing Yi, 28-10-1, living culture: JZB 3290001.

GenBank number: ITS: MW130255.

Notes: Phyllosticta is an important genus of plant pathogens and contains quarantinable pathogenic species in some countries, especially in Europe (Wulandari et al. 2013). Phyllosticta hostae was introduced by Su and Cai (2012) from Hosta plantaginia (Liliaceae). This is the first record of P. hostae causing leaf spots in rose in China.

Fig. 19 Phyllosticta hostae (JZB 3290001). a Leaf spot on rose leaf. b Front view of the colony on PDA. c Rear view of the colony on PDA. D Conidiomata in culture. e–h Conidia. Scale bars: d = 100 µm, e–h = 10 µm