Phlyctema Desm., Annls Sci. Nat., Bot., sér. 38: 16 (1847)
Facesoffungi number: FoF 07493
Leotiomycetes, Leotiomycetidae, Medeolariales, Dermateaceae
Saprobic, parasitic or endophytic on plant host in terrestrial habitat, such as Aconitium napellus (Ranunculaceae), Coronilla sp. (Fabaceae), Erigeron sp. (Asteroideae), Malus pumila, M. sylvestris (Rosaceae) (Sutton 1980, Chen et al. 2016, this study). Sexual morph: Apothecia circular or irregular and merged, sessile, slightly convex, developing from acervuloid stromata. Asci 8-spored, cylindrical-clavate, inoperculate, apical apparatus turning blue in iodine. Ascospores hyaline, elongated ellipsoid, rounded or somewhat pointed at both ends, straight or slightly curved, aseptate when young, septate at maturity. Paraphyses hyaline, numerous, filiform, branched, septate, slightly swollen at apical cell (Guthrie 1959, Verkley 1999). Asexual morph: Conidiomata yellowish brown to brown, pycnidial, solitary or gregarious, immersed to semi-immersed, globose to subglobose, unilocular, thick-walled, glabrous. Ostiole absent, dehiscence by rupture of the overlying tissues. Conidiomata wall composed of thick-walled, dark brown cells of textura angularis in outer layers, becoming thin-walled, hyaline cells in inner layers. Conidiophores arising from the inner wall layers of conidiomata, hyaline, cylindrical to subcylindrical, broaden at the base, branched irregularly. Macroconidiogenous cells hyaline, enteroblastic, phialidic, ampuliform to subcylindrical, usually intergrated, determinate, with a wide channel and minute collaratte and periclinal wall thickening. Macroconidia hyaline, subcylindrical to fusiform, usually curved, aseptate, guttulate, smooth-walled. Microconidiogenous cells hyaline, enteroblastic, phialidic, subcylindrical to ampuliform, smooth-walled. Microconidia hyaline, filiform with rounded ends, unicellular, straight or curved.
Type species: Phlyctema vagabunda Desm., Annls Sci. Nat., Bot., sér. 3 8: 16 (1847)
Notes: The filiform, curved microconidia of Phlyctema can be confused with Diaporthe and Libertella. However, Diaporthe was seprated from Phlyctema by its fusiform to oval or ellipsoid macroconidia. Libertella lacks macroconidia, but differs from Phlyctema by its holoblastic, sympodial, integrated conidiogenous cells with 2 to several, slightly protuberant conidiogenous loci (Sutton 1980).
More than 80 species have been recognized in Phlyctema although most have not been re-examined (Index Fungorum 2019). The sexual morph of P. vagabunda was assigned to Neofabraea alba (E.J. Guthrie) Verkley, making Phlyctema a synonym of Neofabraea (Verkley 1999, Johnston et al. 2014). Chen et al. (2016) treated Phlyctema and Neofabraea as separate genera based on morphological characters and multi-gene phylogenetic analyses. We utilized multi-gene analyses to delineate genera in Dermateaceae and also showed Phlyctema to be distinct from Neofabraea. A new collection from dead stems of Coronilla sp. clusters with Phlyctema sensu stricto with high bootstrap value, and it is introduced as a new species in Phlyctema (see notes under P. coronillae).
Distribution: Australia, Canada, Chile, Czechia, Eire, France, Germany, New Zealand, South Africa, Tasmania, UK, USA (Sutton 1980, Chen et al. 2016).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.