Cucurbitariaceae G. Winter [as ‘Cucurbitarieae’], Rabenh. Krypt.-Fl., Edn 2 (Leipzig) 1.2: 308 (1885).
MycoBank number: MB 80667; Index Fungorum number: IF 80667; Facesoffungi number: IF 08179, 181 species.
Necrotrophic or saprobic on woody plants or parasitic on other fungi. Sexual morph: Ascomata immersed, semi-immersed, becoming erumpent, to nearly superficial, scattered, or clustered on basal hypostroma, base not easy to remove from the substrate, usually containing host particles, globose to subglobose, turbinate, lenticular or pyriform, brown to black, surface verruculose to coarsely tubercular ostiolate. Ostiole black, inconspicuous or papillate to cylindrical, ostiolar canal filled with hyaline cells or sometimes periphysate. Peridium composed of several layers of textura angularis cells, light brown to reddish-brown, smooth to rough, or hairy. Hamathecium comprising dense, filiform, hyaline, filamentous, septate, cellular pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, cylindrical to clavate, with furcate pedicel and minute ocular chamber. Ascospores 1-seriate, or partially overlapping, ellipsoidal, golden brown to dark brown, multi-septate, muriform, constricted at the septa, rarely with a gelatinous sheath, sometimes with appendage cells. Asexual morph: Coelomycetous, phoma- or pyrenochaeta-like (Hyde et al. 2013, Wanasinghe et al. 2017d, Jaklitsch et al. 2018a).
Type – Cucurbitaria Gray
Notes – Cucurbitariaceae is a well-supported monophyletic family in Pleosporales (Doilom et al. 2013, Hyde et al. 2013, Wijayawardene et al. 2014b, Li et al. 2016a). The family was introduced by Winter (1885) and typified by Cucurbitaria berberidis. Intergeneric classification based on phenotypes within Cucurbitariaceae has often been controversial. For example, Barr (1987b) considered ‘turbinate or globose or ovoid ascomata, with warted or nearly smooth surfaces, cylindrical or slightly clavate or oblong asci, symmetric and ellipsoid or fusoid or asymmetric and oblong or elongate ascospores’ as general features of Cucurbitariaceae and considered the family to belong in Pleosporales. Considering the above phenotypic features, genera such as Cucurbitaria, Cucurbidothis, Otthia, Rhytidiella and Syncarpella were also included in the family (Wanasinghe et al. 2017d). Later phylogenetic studies have shown that Cucurbitariaceae is a heterogeneous group and recent studies have excluded some genera from this family and referred other genera to the family (Hyde et al. 2013, Doilom et al. 2013, Wanasinghe et al. 2017d, Valenzuela-Lopez et al. 2018).
Doilom et al. (2013) revisited Cucurbitariaceae based on DNA sequence data, examination of type species and links to asexual morphs. They epitypified Cucurbitaria berberidis with molecular data and a pyrenochaeta-like asexual morph, illustrated Curreya, Rhytidiella and Syncarpella from their holotypes and discussed their familial affinities. Hyde et al. (2013) also provided a comprehensive transcript to this family with illustrations. Wijayawardene et al. (2014b) included Cucurbidothis, Cucurbitaria, Curreya, Pyrenochaeta, Pyrenochaetopsis, Rhytidiella and Syncarpella as conventional genera in Cucurbitariaceae. However, Cucurbitariaceae members comprise many epithets in Index Fungorum (Doilom et al. 2013) and only a few species have DNA sequence data in GenBank. Thambugala et al. (2015b) introduced a new genus, Neocurreya for Curreya austroafricana, C. grandicipis and C. proteae in Floricolaceae (Pleosporales) based on evidence from morphology and phylogeny. The placement of the type species of Curreya, C. conorum is unclear as the latter has not been cultured and there is no DNA sequence data in databases to verify its phylogenetic affinities. Fenestella is relatively poorly studied and the type species of the genus could not be located. Therefore, Phookamsak & Hyde (2015) revisited
Fenestellaceae and transferred Lojkania to Testudinaceae, maintaining Fenestella in Fenestellaceae. Wanasinghe et al. (2017) introduced two new taxa which are typical of Fenestella viz. F. ostryae and F. mackenziei. Phylogenetically, these strains shared a close phylogenetic affinity to F. fenestrata within Cucurbitariaceae. Thus, with their updated phylogeny where Fenestellaceae was nested in between Cucurbitariaceae and with insufficient morphological grounds to support Fenestellaceae as an independent family, they proposed Fenestella to be transferred to Cucurbitariaceae and Fenestellaceae be synonymized with Cucurbitariaceae.
Jaklitsch et al. (2018a) provided a comprehensive account for Cucurbitariaceae including multi-gene (ITS, LSU, rpb-2, SSU, tef1 and tub2) phylogenetic analyses. They recognised two new species in Cucurbitaria and 19 in Neocucurbitaria (which was introduced by Wanasinghe et al. 2017d). Astragalicola, Cucitella, Parafenestella, Protofenestella, and Seltsamia were described as new genera. Also, they reported that Fenestella should be restricted to the type species F. fenestrata. In addition, they have transferred F. mackenziei and F. ostryae to Parafenestella based on their lack of molecular support with Fenestella and the absence of a well-delimited pseudostromata and ascospore septation. Jaklitsch & Voglmayr (2020) re-evaluated the boundaries and species composition of Fenestella and related genera of the Cucurbitariaceae. They recognised eight species, of which five are new, in Fenestella, 13 in Parafenestella with eight new species and two in the new genus Synfenestella with one new species.