Tandonella S.S. Prasad & R.A.B. Verma, Indian Phytopath. 23(1): 112 (1970).
Associated with leaf spot. Sexual morph: Unknown. Asexual morph: Mycelium in vivo immersed and superficial, subhyaline to pigmented, branched, septate, thin-walled. Stromata superficial, small, brown, pseudoparenchymatic. Conidiomata synnematous, synnemata composed of parallel threads, determinate, solitary or grouped, erect, brown, apically lax, splaying out. Individual conidiophores filiform, usually unbranched, septate, pigmented, smooth to rough-walled. Conidiogenous cells integrated, terminal or intercalary (conidiogenous region terminal, rarely lateral or extending down the synnemata), proliferation sympodial, geniculate, cicatrized, conidiogenous loci conspicuous, slightly thickened, darkened-refractive, often protuberant. Conidia holoblastically formed, catenate, in short simple or branched chains, ellipsoid ovoid, fusiform, cylindrical, aseptate to euseptate, pigmented, rough-walled, hila somewhat thickened and darkened-refractive (adapted from Sutton and Pascoe 1987 and Videira et al. 2017).
Notes: Tandonella is characterised by immersed and superficial mycelium, synnematous conidiomata, integrated, terminal or intercalary conidiogenous cells, holoblastic ellipsoid, ovoid, fusiform, or cylindrical, aseptate to euseptate conidia. Sutton and Pascoe (1987) re-studied the holotype specimen of T. ziziphi (IMI 112255) and provided an updated description of the genus. Sutton and Pascoe (1987) also added the new species Tandonella oleariae. Castaneda and Kendrick (1990) described T. cubensis found from Bauhinia divaricata in Cuba. Species of Tandonella differ in conidial morphology. Crous and Braun (2003) and Braun et al. (2013) treated Tandonella as a synonym of Passalora but this was not confirmed by molecular data. In the phylogenetic analyses of Videira et al. (2017), T. cubensis (CBS 500.92) clustered within Pseudocercospora. Tandonella differs from Pseudocercospora in having long synnematous fascicles, dark brown at the base and brown above, brown, polyblastic conidiogenous cells and brown, falcate conidia formed in chains. Several authors added new species to Tandonella (Prasad and Verman 1970; Guo and Liu 1986; Srivastava et al. 1994; Zhai et al. 2006). The placement of Tandonella in Mycosphaerellaceae is doubtful.