Paraconiothyrium estuarinum Verkley & Manuela Silva, in Verkley et al., Stud. Mycol. 50(2): 327 (2004).

Index Fungorum number: IF 500081; MycoBank number: MB 500081; Facesoffungi number: FoF 00054

Saprobic in terrestrial environments. Asexual state: Conidiomata 0.2–0.5(-1) mm diam., mostly submerged in the agar, but also superficial and on the aerial mycelium, eustromatic, globose or flattened, dark brown to black, with several merging cavities, ostioles absent, opening by the dissolution of upper cells. Conidiomatal wall 30–45 μm thick, composed of the outer layer of isodiametric or more flattened cells with hyaline to reddish-brown walls thickened up to 1.5 μm, lined by a 35–60(-75) μm thick inner layer of textura angularis, the surface of the conidiomatal wall often covered under brown entangling hyphae. Conidiogenous cells 4–6.5 × 2.5–3.5(-4) μm, discrete, assembled into protruding masses of cells, or integrated into very compact conidiophores, ampulliform to subcylindrical, hyaline, indeterminate, phialidic with an inconspicuous periclinal thickening and collarette, later often with a single percurrent proliferation, mostly. Conidia narrowly ellipsoidal or short-cylindrical, straight or slightly curved, rounded at both ends, 1-celled, with one or two small, polar guttules, and with thin and smooth walls that are hyaline at secession, but soon becoming olivaceous- or yellowish-brown. Sexual state: unknown (Verkley et al. 2004).

Notes – Paraconiothyrium was introduced by Verkley et al. (2004) to accommodate four new species, Parac. estuarinum, Parac. brasiliense, Parac. cyclothyrioides, and Parac. fungicola. Based on the combination of ITS and partial SSU nrDNA sequences Verkley et al. (2004), included Coniothyrium minitans and the ubiquitous soil fungus Coniothyrium sporulosum in Paraconiothyrium. In the same study, the asexual morphs of Paraphaeosphaeria michotii and P. pilleata were regarded as representative of Paraconiothyrium, but remained formally unnamed. Paraconiothyrium species are phylogenetically distant from typical members of the other coelomycete genera such as Coniothyrium, Microsphaeropsis, Cyclothyrium, and Cytoplea. In Paraconiothyrium, the conidiomata generally are complex, eustromatic and relatively thick-walled. They may appear as simple pycnidia, but then they usually lack a well differentiated ostiole. In Coniothyrium, the conidiomata are true pycnidia, which may merge in vitro but then always produce well-developed, sometimes even papillate ostioles. The most distinctive Coniothyrium feature is the annellidic conidiogenous cells, which percurrently proliferate after secession of each conidium. Coniothyrium conidia are thick-walled and verruculose, with a truncate base and sometimes a basal frill (Sutton 1980). Microsphaeropsis species are also pycnidial, but their conidiogenous cells are discrete, Phoma-like phialides, which only rarely proliferate percurrently. Microsphaeropsis olivacea, the type species, has pale brown, 1-celled, thin- and smooth-walled conidia (Verkley et al. 2004).

Câmara et al. (2001) assessed morphological data in relation to ITS sequences for nine species of Paraphaeosphaeria, and identified three lineages, which were later confirmed by SSU data (Câmara et al. 2003). They found that only one species, Paraph. pilleata, was congeneric with the type species Paraph. michotii (Verkley et al. 2004). Thus, only two species were retained in Paraphaeosphaeria sensu stricto. For the other species the genera Phaeosphaeriopsis and Neophaeosphaeria were erected. Following multi-locus DNA analysis and detailed morphological study, Verkley et al. (2014) were able to delimit and formally propose nine new species and two new genera among the fungi in the Montagnulaceae formerly recognizable as Coniothyrium-like asexual morphs. Verkley et al. (2014) suggested that the genus Paraconiothyrium appears to be paraphyletic within the family Montagnulaceae but proposed that it should not be split up to further genera.

In the present study, we also observed similar phylogeny, where Paraconiothyrium appears to be paraphyletic within the family Didymosphaeriaceae. Several sexual stages of some Paraconiothyrium species were reported during the study, i.e., the sexual state of Paraconiothyrium fuckelii (MFLUCC 13-0043) and novel species of Paraconiothyrium, Parac. magnoliaee introduced from Thailand and are described below.