Ascitendus austriacus (Réblová et al.) J. Campb. & Shearer
≡ Ascolacicola austriaca Reblová et al.
Sexual morph: Ascomata on wood separate to clustered, densely aggregated in patches, immersed to superficial, black, coriaceous, globose to subglobose, ostiolate with a prominent neck, venter 350–585 ´ 295–505 µm. Ascomal wall in longitudinal section 28–42 µm thick, comprised of three layers: outer layer of pseudoparenchyma cells occluded with brown amorphous material; middle layer of brown, thin-walled, laterally compressed, elongated cells; inner layer of hyaline, laterally compressed, elongated, hyaline cells; in surface view, black, opaque. Neck central, cylindrical, periphysate, 85–300(–460) ´ 50–140 µm, black at base, pale yellow at apex, wall 2-layered, outer layer of dark brown, laterally compressed thin-walled cells occluded with brown amorphous material, inner layer of laterally compressed thin-walled hyaline cells. Hamathecium paraphysate; paraphyses longer than asci, 120–190 µm long, 4–10 µm broad at base, tapering to 2–3 µm, 1–9 septate. Asci functionally unitunicate, cylindrical, 100–160 ´ 4–6 µm, expanding up to 260 ´ 8 µm in water, separating from the hymenial layer, pedicellate, with a prominent cylindrical to flaring apical apparatus, 2.5–3.5 (µm long, 3.0–3.8 µm wide at apex, 2–3 µm wide at base; ascus apparatus MLZ negative, staining positive in aqueous cotton blue (for mature asci only) and nigrosin, discharging ascospores through the ascus apical ring or by dissolution of lower one-third to one-half of ascus when in water. Ascospores pale brown, fusoid, curved, 3-septate in sequence 2:1:2 or 3:1:2, 14–27 ´ 4–9 µm, middle cells darker than outer cells, each cell with a single large guttule, not constricted at septa; septa prominent, pigmented brown, with small refractive dots at ends; wall roughened in a striated pattern; without appendages or a sheath. Asexual morph: Unknown.
Characteristics in culture: Colonies on PYG agar immersed, brown, spreading, comprised of brown, septate, branched hyphae.
Etymology: The epithet austriacus refers to the country from which this species was originally collected (Reblova and Winka 2001)
Distribution: AUSTRALIA, Wien 19, Herman-nskogel, on wood of Fagus sylvatica submerged in a stream (Réblová & Winka 2001), CANADA, Ontario and Manitoba, on submerged wood; USA, on submerged wood; Venezuela, on submerged wood (Campbell & Shearer 2004).
Notes: Holotype PRM 842991. LSU sequence data is available.
Campbell J, Shearer CA (2004) Annulusmagnus and Ascitendus, two new genera in the Annulatascaceae. Mycologia 96:822–833.
Luo ZL, Hyde KD, Liu JK, Maharachchikumbura SSN et al. 2019 – Freshwater Sordariomycetes. Fungal Diversity 99, 451–660.
Réblová, M.; Winka, K. 2001. Generic concepts and correlations in ascomycetes based on molecular and morphological data: Lecythothecium duriligni gen. et sp. nov. with a Sporidesmium anamorph, and Ascolacicola austriaca sp. nov. Mycologia. 93(3):478-493.
Figs. 10-16. Ascitendus austriacus. 10. Longitudinal section through ascoma. 11. Longitudinal section through peridium. 12. Cylindrical neck with hyaline upper region. 13. Ascus apical ring, stained with aqueous nigrosin. 14. Septate, tapering paraphysis. 15. Ascus expanded in water. 16. Deciduous ascus. Bar = 10 µm, except Fig. 10 = 100 µm.
Figs. 17-25. Ascitendus austriacus. 17. Ascus illustrating dissolution of lower part of ascus (arrowed). 18-20. Ascospores with dark pigmented septa and lighter end cells. 18. Within the ascus. 19, 20. Released from ascus. 21-23. Ascitendus austriacus Holotype. 21. Ascus apical ring. 22. Ascospores. 23. Deciduous ascus. 24, 25. Ascospores illustrating roughened walls in a striated pattern. 24. Holotype specimen. 25. Additional specimen. Bar =10 µm.