Schizotheciaceae Y. Marin & Stchigel, Microorganisms 8: 1430, 24. 2020

MycoBank number: MB 835507; Index Fungorum number: IF 835507; Facesoffungi number: FoF14648

Etymology – Based on the genus Schizothecium, the oldest representative genus in the family.

Type genusSchizothecium Corda, Icon. Fung. (Prague) 2: 29. 1838.

Sexual morph Ascomata ostiolate, immersed, semi-immersed, or superficial, scattered or aggregated, light to dark brown or black, globose to subglobose, pyriform, pyriform-conical, ovoid or obpyriform, glabrous or covered with flexous hairs, sometimes upper part of the ascomata adorned with groups of swollen agglutinated hairs, or with prominent protruding ascomatal cells; neck short or long, dark brown to black, opaque, conical, cylindrical, or elongate, papillate, sometimes with short, thick-walled, swollen cells, or swollen agglutinated hairs, or long, sometimes agglutinated, rigid hairs not forming fascicles, or with tufts of brown to black, rigid, agglutinated, septate, long, thick hairs. Ascomatal wall pseudoparenchymatous, membranaceous, occasionally semi-coriaceous, semi-transparent, occasionally dark brown to black and opaque, yellowish to light brown, textura angularis, textura globulosa, or textura epidermoidea. Paraphyses and periphyses absent or present. Asci unitunicate, 4- to 8-spored, clavate, cylindrical, broadly ellipsoid, or broadly fusiform, apically rounded, long or short stipitate, apical ring absent or present, dehiscing below the apex. Ascospores uniseriate, biseriate, or irregularly arranged, one- or two-celled; one-celled ascospores uniseriate or biseriate, hyaline, turning pale brown, golden, ochraceous, dark brown, or blackish brown at mature, cylindrical, fusiform or ellipsoidal, sigmoid or geniculate, one end may become swollen and turn brown, smooth-walled, without or with a germ pore at one or both ends, sometimes with a gelatinous appendage at each end, sometimes with a striated gelatinous sheath surrounding whole ascospore; two-celled ascospores at first one-celled, hyaline, clavate, cylindrical or spatuliform, mostly becoming transversely uniseptate, occasionally developing two terminal ellipsoid black cells that remain connected with the long, often undulating, hyaline middle part of the spore, with a germ-pore at the free end and secondary appendages gelatinous arranged in rings around the top and base of the colored cells; upper cell olivaceous to brown to dark brown, globose, navicular, ellipsoidal, ellipsoidal-fusiform, fusiform, fusiform-obovoid, obovoid, or polygonal with five angles in side view, smooth-walled, finely granulated, pitted, ornamented with spines, or warted, sometimes with warts arranged forming ridges or large spots, with an apical or subapical germ pore; lower cell hyaline to pale brown, conical, cylindrical, cylindrical-obclavate, obclavate or obconical, collapsing or long persistent, smooth-walled to slightly warted; apical gelatinous appendages absent or present, attached at each end, lash-like; gelatinous sheaths rarely present, striated, swelling in water. Asexual morph absent or present. Conidiophores reduced to conidiogenous cells. Conidiogenous cells sometimes present, phialidic. Conidia hyaline to pale brown, ovoid to clavate or elongate, almost smooth-walled, usually produced laterally or terminally on undifferentiated hyphae, solitary.

Notes – This family is introduced to accommodate lasiosphaeriaceous taxa located in a well-supported clade (80% bs/1 pp; clade VIII, Figure 2), distinct from Lasiosphaeriaceae s. str. (clade V, Figure 1). It includes the genera Echria, Immersiella, Jugulospora, Pseudoechria, Pseudoschizothecium, Rinaldiella, Rhypophila, Schizothecium, and Zygopleurage, but also several species of Apiosordaria and Zopfiella. However, the type species of these latter genera are located in the Podosporaceae (clade IV) and in the Lasiopshaeriaceae s. str.   (clade V), respectively.   Consequently, those species that fall into clade VIII must be reviewed before they are moved to other (new) genera. Two species of Arnium, i.e., A. cirriferum and A. hirtum, are also included in this family. Arnium is a polyphyletic genus scattered throughout the order Sordariales, and its type species (A. lanuginosum) has not been sequenced. Finally, a strain identified as Cercophora mirabilis (which is the type species of the genus) was also located in the Schizotheciaceae, but its morphological study was not possible to confirm the identification, because the colonies remained sterile on different culture media. Due to this inconvenience, further studies are needed for the correct placement and delimitation of the genus Cercophora. The Schizotheciaceae are characterized by the production of mostly ornate, ostiolate ascomata with different kinds of structures: Schizothecium presents short swollen agglutinated hairs or prominent protruding ascomatal wall cells; Echria and Pseudoechria produce tufts of long rigid agglutinated hairs, while Pseudoschizothecium produces warts composed of small polygonal cells. The ascomatal wall is mostly pseudoparenchymatous, membranaceous, and semi-transparent. Ascospores display a large amount of variability including taxa with one- or two-celled ascospores, as well as ascospores with two independent cells that remain connected by a long, often undulating, hyaline middle part.

In the Schizotheciaceae, a well-supported clade (100% bs/1 pp; Figure 2) was composed of a reference strain of Jugulospora rotula, ATCC 38359; a reference strain of Strattonia carbonaria, ATCC 34567; the type strains of Apiosordaria antarctica, Apiosordaria globosa, Apiosordaria hispanica, and Apiosordaria vestita, CBS 381338, CBS 110113, CBS 110112, and IMI 381338, respectively; and an isolate morphologically identified by us as Rhexosporium terrestre, FMR 12428. All these taxa produce similar ascomata (with a translucent ascomatal wall and dark brown papillate neck), and clavate and early septate ascospores with the upper cell warted or finely granulate. Therefore, all these taxa are transferred to the genus Jugulospora, which is also emended.