Taxonomy and phylogeny of Cercospora spp. from Northern Thailand Author Nguanhom, Jeerapa Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, 50200, Thailand Author Cheewangkoon, Ratchadawan Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, 50200, Thailand Author Groenewald, Johannes Z. CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands Author Braun, Uwe Martin-Luther-Universität, Institut für Biologie, Bereich Geobotanik und Botanischer Garten, Herbarium, Neuwerk 21, 06099 Halle (Saale), Germany Author To-Anun, Chaiwat Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, 50200, Thailand Author Crous, Pedro W. CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands & Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, South Africa text Phytotaxa 2015 2015-10-30 233 1 27 48 http://dx.doi.org/10.11646/phytotaxa.233.1.2 journal article 10.11646/phytotaxa.233.1.2 1179-3163 13631906 Cercospora musigena Nguanhom, Crous & U. Braun , sp. nov. ( Fig. 5 ). MycoBank MB812921 Type:— THAILAND . Chiang Mai : on leaves of Musa sp. ( Musaceae ), 27 May 2013 , S . Seekanha ( holotype CBS H-22292, culture ex-type CPC 24809 = CBS 140167, CPC 24831). FIGURE 5. Cercospora musigena (CBS H-22292). A. Leaf spot; B, C. Conidiophores and conidiogenous cells; D− H. Conidia.—Scale bars: B− C = 50 μm; D− H = 30 μm. Leaf spots irregular, pale brown along the leaf margins, often surrounded by a yellow halo. Caespituli amphigenous, punctiform, brown. Stromata intraepidermal to subepidermal, brown, 30−45 μm diam. Conidiophores in moderately large fascicles (11−20 per fascicle), erumpent through the cuticle, brown, paler toward the apex, 3−5-septate, cylindrical, 1−3 times geniculate in upper part, tapering to flat-tipped loci, branched, 30−75 × 4−5 μm. Conidiogenous cells proliferating sympodially 1−4 times, integrated, terminal, rarely intercalary; conidiogenous loci distinct, apical or formed on shoulders due to sympodial proliferation, thickened and darkened, protruding, 2−3 μm diam. Conidia solitary, hyaline, straight to mildly curved, acicular, truncate at the base, obtuse at the apex, thin-walled, smooth, 15−130 × 3−5 μm, 2−20-septate, hila thickened, darkened, 2–2.5 μm diam. Culture characteristics: —Colonies spreading, flat, with sparse to dense aerial mycelium, even margin, reaching 48 mm diam after 2 wk. On MEA surface pale purplish grey, with rosy buff outer region; reverse sepia. On PDA surface vinaceous-buff, with red diffuse pigment surrounding culture; reverse bay. On OA surface whitish, with patches of grey; reverse chestnut, with rust in outer region. Etymology: —Named after the host from which it was isolated, Musa sp. Notes: — Cercospora musigena is similar to C. hayi Calp. by its acicular conidia with truncate bases, being part of the C. apii complex ( Braun et al. 2014 ). In C. hayi , however, there are fewer conidiogenous loci per conidiogenous cell, and the conidial tips are acute to subacute ( Calpouzos 1955 ). C. apii s. lat. (including C. hayi ) on Musa spp. is genetically heterogeneous. Sequences retrieved from C. apii -like cultures isolated from banana clustered in three different clades ( Groenewald et al. 2013 ). However, the identity of the name C. hayi is still unresolved and will need to be clarified by means of epitypification ( Braun et al . 2014 ).