Myrmecridiaceae Crous, Persoonia 34: 219 (2015)
Index Fungorum number: IF812461; 16 species.
Saprobic on decaying wood submerged in freshwater, leaf litter, on stem or leaves of herbaceous plants, occurring on soil and in house dust (Crous et al. 2015b, c, 2016b, 2018b, c, Peintner et al. 2016, Réblová et al. 2016a, Tibpromma et al. 2017b). Sexual morph: Ascomata immersed, solitary or aggregated, with subglobose to conical venter and ostiolate papilla as well as dark brown clypeus, glabrous. Ostiole periphysate. Peridium leathery, two-layered with hyaline to pale brown outer layer and subhyaline inner layer consisting of cells of textura angularis to textura prismatica. Paraphyses cylindrical, septate. Asci 8-spored, unitunicate, cylindrical, with a slender long pedicel, apex rounded. Ascospores uniseriate or overlapping uniseriate, hyaline, ellipsoidal, 3-septate, slightly verrucose, with granular content (Réblová et al. 2016a). Asexual morph: In vitro, Mycelium submerged, hyaline, thin-walled. Conidiophores erect from creeping hyphae, unbranched, straight or flexuous, brown at base and paler towards the apex, subcylindrical, smooth, septate. Conidiogenous cells differentiating from the apical region of conidiophore, integrated, polyblastic, cylindrical, subhyaline to brown, with conidium-bearing denticles along the conidiogenous axis. Conidia hyaline to pale brown, ellipsoid to obovoid to fusoid, solitary, smooth or verrucose, aseptate or septate, some species present a wing-like sheath (adapted from Crous et al. 2015c, 2016a, 2018b, c, Peintner et al. 2016, Tibpromma et al. 2017b).

Type genus – Myrmecridium Arzanlou, W. Gams & Crous

Notes – Myrmecridiales and Myrmecridiaceae were established by Crous et al. (2015c) to accommodate Myrmecridium species based on the analyses of LSU sequence data. Myrmecridiaceae is the type family of Myrmecridiales (Sordariomycetes). Myrmecridiales is a monotypic order in the subclass Diaporthomycetidae (Crous et al. 2015c) and has phylogenetic affinities with Distoseptisporaceae and Magnaporthales in a multi-gene phylogenetic tree based on LSU, SSU, tef1 and rpb2 sequence data (Hongsanan et al. 2017). Myrmecridiaceae comprises two genera Myrmecridium (Arzanlou et al. 2007) and Neomyrmecridium (Crous et al. 2018b).

Ecological and economic significance of Myrmecridiaceae
As a member of soil fungal community, Myrmecridium species are positively related with the
death rate of notoginseng, which is a valuable herbal medicine (Dong et al. 2016). Myrmecridium species also occur in the sugarcane rhizosphere, and might have a potential as biocontrol agents against pathogens (Romão-Dumaresq et al. 2016). Myrmecridium schulzeri is an excellent decomposer of wood of oak and pine. It was observed in the third stage of fungi succession during wood decomposition (Wrzesień et al. 2016). Some Myrmecridium species displayed relatively high antibacterial activity (Zhang et al. 2012a) and glyphosate-tolerance (Schlatter et al. 2017b). Myrmecridium taxa showed high abundance in live and dying glyphosate-killed wheat roots and may play an under-recognized role in green bridge dynamics of glyphosate degradation (Schlatter et al. 2017a)