Mycoarachis inversa Malloch & Cain, Can. J. Bot.

Melo, Roger Fagner Ribeiro, Maia, Leonor Costa & Miller, Andrew Nicholas, 2017, Coprophilous ascomycetes with passive ascospore liberation from Brazil, Phytotaxa 295 (2), pp. 159-172 : 166

8. Mycoarachis inversa Malloch & Cain, Can. J. Bot. 48(10): 1822 (1970)

( Plate 1, Figs. 18–21)

Ascomata non-ostiolate, scattered, semi immersed to superficial, globose to subglobose, dark green to black, 110–215 μm diam., glabrous, with a metallic appearance at reflected light, formed directly on dung or on wet paper in incubation. Peridium pseudoparenchymatous, membranaceous, opaque, with two distinct layers, the outermost composed of one to four inflated globose, angular or elongated, thin-walled, hyaline cells, 5–20 μm diam., the innermost composed of flattened, angular (textura angularis), dark brown, thick-walled cells, 5–17.5 μm diam. Asci 8-spored, globose to subglobose, 5–10 μm diam., evanescent. Ascospores 2-celled, peanut-shaped, with a marked constriction at the central septum dividing them into two globose cells, smooth, hyaline, 3–5 × 2–2.5 μm, lacking conspicuous germ pores.

Material examined: — BRAZIL. Pernambuco, Instituto Agronômico de Pernambuco ( IPA), Caruaru , on cattle dung, 12 Dec 2012, R. F. R. Melo ( URM86655 a!, 86655b!) ; Serra Talhada , on cattle dung, 30. May 2012, R. F. R. Melo ( URM86656 !), 15 Oct, R. F. R. Melo 2012 ( URM86657 a!, 86657b!) .

Habitat: —Elephant and cattle dung, as well as on dung of unknown origin.

Distribution: —Africa ( Tanzania, Uganda) and North America ( United States). This is the first record for Brazil.

Notes:— Mycoarachis inversa , which until 1988 was the only representative of Mycoarachis , can be easily recognized by the small cleistothecia presenting a thick layer of hyaline cells in the outer peridium, as if the peridium were turned inside out, “reverse”, as suggested by the epithet’s etymology, and by the shape of ascospores. It differs from M. tetraspora Valldosera & Guarro (1988:231) mainly by having 8-spored asci.