Lichenoconiaceae Diederich & Lawrey, in Hyde et al., Fungal Diversity 63: 131 (2013).
= Abrothallaceae Pérez-Ort. & Suija, in Pérez-Ortega, Suija, Crespo & Ríos, Fungal Diversity 64(1): 303 (2014).
MycoBank number: MB 803667; Index Fungorum number: IF 803667; Facesoffungi number: FoF 08046, 58 species.
Parasitic or parasymbiotic on lichen thalli. Vegetative hyphae immersed in lichen thallus, usually hyaline, I+ violet in some species. Sexual morph: Ascomata apothecioid, solitary or in groups, superficial, rounded, convex to almost globose, rarely flattened, black or dark brown, some species with greenish pruina, at least in young stages. Proper exciple thin, usually disappearing when mature, composed of radiating hyphae. Hymenium hyaline or greenish in the upper part, covered with light to dark brown or reddish granules dissolving in KOH. Hypothecium light to dark brown, composed of isodiametric cells (textura angularis type). Hamathecium comprising septate, anastomosed and irregularly dichotomously branching interascal filaments. Asci 4–8-spored, thick-walled, bitunicate, functionally fissitunicate, ovate to clavate, apedicellate, with a distinct ocular chamber, I-. Ascospores 2-seriate, irregularly or 2-seriately arranged within the ascus, ellipsoid to broadly ellipsoid, light to dark brown, 1- to 3-septate, asymmetric and soleiform, splitting into part-spores within the ascus in some species, wall finely ornamented to verrucose. Asexual morph: Coelomycetous. Vouauxiomyces-type, pycnidium immersed, semi-immersed or almost superficial, black, with a small ostiole. Pycnidial wall thick-walled, comprises isodiametric cells (textura angularis-type). Conidiophores reduced. Conidiogenous cells percurrently proliferating, ampulliform to lageniform, lining the cavity of the pycnidium, hyaline, smooth-walled. Conidia holoblastic, clavate to obpyriform or almost roundish, hyaline to dark brown, smooth to slightly echinulate, usually embedded in mucilage.
Type: Lichenoconium Petr. & Syd.
Notes: Lawrey et al. (2011) studied the phylogenetic affinities of Lichenoconium, a genus of lichenicolous fungi known only in its asexual morph. They found that Lichenoconium is also a member of Dothideomycetes, and subsequently, Hyde et al. (2013) introduced a new order Lichenoconiales to accommodate it. Pérez-Ortega et al. (2014) introduced Abrothallaceae and the new order Abrothallales for the lichenicolous genus Abrothallus. The classification of this genus had long been debated. This is one of the few Dothideomycetes genera having apothecioid ascomata, but the bitunicate asci and the shape of interascal filaments clearly segregates it from other similar groups (Pérez-Ortega et al. 2014). Pérez-Ortega et al. (2011) established the connection between the sexual morph Abrothallus and the asexual morph Vouauxiomyces. Vouauxiomyces and Lichenoconium share many features, such as the mode of conidiogenesis and shape of conidia (detailed descriptions in Hawksworth 1981b), although the conidia are hyaline in Abrothallus (except in Abrothallus kamchatica) and dark brown in Lichenoconium. Recent phylogenetic analyses recovered Abrothallus and Lichenoconium as sister genera, with a relatively young split (9 MYA) raising the question of the need to keep two separate orders (Liu et al. 2017). Diederich et al. (2018) in their review of lichenicolous fungi treated Lichenoconiales as a synonym of Abrothallales, and Lichenoconiaceae as a possible synonym of Abrothallaceae.