Colletotrichum Corda, in Sturm, Deutschl. Fl., 3 Abt. (Pilze Deutschl.) 3(12): 41 (1831)
Hypocreomycetidae, Glomerellales, Glomerellaceae, Colletotrichum
Index Fungorum number: IF7737; Facesoffungi number: FoF 00144; 894 morphological species; <250 species with sequence data (Jayawardena et al. 2016).
Parasitic, endophytic and saprobic on plant leaves, stems and fruits. Sexual morph: Ascomata solitary or gregarious, globose to subglobose, dark brown to black, ostiolate. Ostiole periphysate. Peridium composed of pale to medium brown flattened cells of textura angularis. Paraphyses hyaline, septate, branched at the base, rounded at the apex. Asci 8-spored, unitunicate, cylindrical to subfusoid, short pedicellate, with a J-, refractive ring at the apex. Ascospores uni- to biseriate, hyaline, aseptate, smooth walled, cylindrical, oval, fusiform or rhomboid, straight or curved, one end ± acute and one end rounded or both ends rounded. Asexual morph: Coelomycetous. Conidiomata acervular, ranging from sporodochia-like aggregations to closed conidiomata that open by rupture, conidiophores and setae formed on cushions of pale to medium brown, roundish to angular cells. Setae may or may not be present, straight, pale to dark brown, sometimes hyaline towards the tip, smooth-walled, verruculose to verrucose, 1–8-septate, base cylindrical, conical or slightly inflated, tip ± rounded to ± acute. Conidiophores hyaline to pale brown, simple or septate, branched or unbranched, smooth- walled, sometimes verruculose. Conidiogenous cells enteroblastic, hyaline to pale brown, smooth- walled, discrete, ampulliform, cylindrical, doliiform or ellipsoidal, collarette usually distinct, periclinal thickening visible to conspicuous, sometimes extending to form new conidiogenous loci (percurrent) or surrounded by a gelatinous coating. Conidia hyaline, smooth-walled, aseptate, cylindrical, clavate, fusiform, sometimes ellipsoidal to ovoid, straight or curved, apex rounded to acute, at times with a filiform appendage, base rounded to truncate, sometimes with a prominent hilum. Appressoria single or in small groups, pale to dark brown, with a globose, elliptical, clavate, navicular or irregular outline and an entire, undulate or lobate edge (adapted from Maharachchikumbura et al. 2016b).
Type species: Colletotrichum lineola Corda, in Sturm, Deutschl. Fl., 3 Abt. (Pilze Deutschl.) 3(12): 41 (1831)
Notes: The genus Colletotrichum was introduced by Corda (1831) for C. lineola Corda (Damm et al. 2009; Cannon et al. 2012b). The genus is the asexual morph of Glomerella, but Colletotrichum was selected for conservation by Maharachchikumbura et al. (2015).
Ainsworth (1971) listed Colletotrichum as a member of the family Phyllachoraceae. However, Barr (1976a) included the genus in Melogrammataceae. Hawksworth et al. (1983) later placed it in its traditional position in Phyllachoraceae, which was adopted by Hawksworth et al. (1995). However, due to its astromatic nature Colletotrichum had been considered to be an outlier within Phyllachoraceae (Cannon et al. 2012b). Preliminary studies together with ontogenetic research confirmed that Colletotrichum and Phyllachora do not belong to the same family (Uecker 1994). Kirk et al. (2001, 2008) placed Colletotrichum in the family Glomerellaceae.
The first attempt to place the genus within a molecular phylogenetic system was carried out with the use of 18S rDNA sequence data (Illingworth et al. 1991; Berbee and Taylor 1992). Winka and Eriksson (2000) considered Colletotrichum to be more closely related to Hypocreomycetidae. The study of Wanderlei-Silva et al. (2003) showed Colletotrichum to be a sister group to Hypocreales. Zhang et al. (2006) confirmed the phylogenetic position of Colletotrichum within the Hypocreomycetidae. Maharachchikumbura et al. (2015) also confirmed the position of the genus in Glomerellaceae. Multi-marker phylogenetic analysis, epitypification and knowledge of species complexes have contributed to a better understanding of the genus (Cai et al. 2009; Hyde et al. 2014).
Colletotrichum orchidis Jayaward., Camporesi & K.D. Hyde