Phacellium Bonord., in Rabenhorst, Fungi europ. exsicc. Edn 2, ser. 2: no. 288 (1860).
Index Fungorum number: IF 9286; Facesoffungi number: FoF 08637, 13 morphological species (Species Fungorum 2022), 1 species with molecular data.
Associated with leaf spots. Sexual morph: Unknown. Asexual morph: Mycelium internal, colorless or faintly colored, often forming stromata in the substomatal cavities, colorless to faintly colored; conidiophores macronematous, synnematous, individual conidiophores simple, rarely branched, continuous to septate, hyaline or almost so, apically and partly laterally splaying out; synnemata at first hyaline, later colored, at least in the lower part, yellowish, yellowish-brown, brown, reddish-brown, flesh-colored; free ends of the conidiophores hyaline. Conidiogenous cells integrated, terminal, polyblastic, sympodial, cicatrized, scars conspicuous, small, somewhat thickened, refractive. Conidia formed singly or catenate, sometimes in branched chains, 0–1-septate, hyaline, smooth to verruculose, shape variable, ellipsoid–ovoid, fusiform, subcylindric, subglobose, irregular, hilum conspicuous, often slightly thickened, refractive (adapted from Braun and Crous 1991).
Type species: Phacellium inhonestum Bonord.
Notes: Phacellium is characterised by colorless or faintly colored mycelium, macronematous, synnematous conidiophores, integrated, terminal, polyblastic conidiogenous cells, and 0–1-septate, hyaline, smooth to verruculose conidia. Braun (1990) discussed the taxonomy of Phacellium and Isariopsis and re-corrected the older, valid name Phacellium. Braun (1998) provided a monograph of Phacellium and accepted 22 species. Braun (1998) listed Mycosphaerella pseudomaculiformis as the sexual morph of P. bulbigerum. Crous et al. (2011) considered Phacellium as a synonym of Ramularia based on R. pusilla. The placement of Phacellium in Mycosphaerellaceae is doubtful. Only ITS sequence data is available for Phacellium veronicae. More taxa with DNA sequence data are needed to confirm the taxonomic position of Phacellium.
Recent NewsRecent paper to be published
Recent SpeciesXylopezia hemisphaerica