Ceratocystis Ellis & Halst., New Jersey Agric. Coll. Exp. Sta. Bull. 76: 14 (1890)
MycoBank number: MB 888; Index Fungorum number: IF 888; Facesoffungi number: FoF 01249; 101 morphological species (Species Fungorum 2020), 53 species with sequence data.
Type species – Ceratocystis fimbriata Ellis & Halst.
Notes – Ceratocystis is characterized by black, globose ascomatal bases with filiform, elongated necks terminating in an ostiole and sticky, hat-shaped ascospores (Upadhyay 1981, Seifert et al. 1993, de Beer et al. 2014). The asexual morph of most Ceratocystis species is chalara- or thielaviopsis-like and characterized by phialidic conidiogenous cells producing chains of hyaline, single-celled, cylindrical conidia called endoconidia, and in some cases secondary dark, barrel-shaped, thick-walled aleurioconidia which are commonly produced that facilitate survival in wood or soil during dry seasons (Hedgcock 1906, Harrington 2013, de Beer et al. 2014, Maharachchikumbura et al. 2016b). The history of Ceratocystis was discussed in Réblová et al. (2011), de Beer et al. (2014), Maharachchikumbura et al. (2016b) and Holland et al. (2019). Ceratocystis species are important plant pathogens and act as causal agents of sap stain in timber and symbiotic associates of insects. For example, C. platani is an invasive alien pathogen of Platanus trees in Europe (Ocasio-Morales et al. 2007), whereas C. albifundus is a virulent pathogen of Acacia mearnsii in Africa (Roux & Wingfield 2013). The ITS, tub1, tef1, rpb2, ms204 gene regions are used to identify species boundaries in Ceratocystis (Marin-Felix et al. 2017, Barnes et al. 2018). The loci rpb2 and ms204 provide stronger resolution among species than tef1 and tub1, but also need to be used in combination with ITS (Fourie et al. 2015).