Fungalpedia – Note 36 Pseudoallosoma

Pseudoallosoma F.B. Rocha, J.L. Bezerra & R.W. Barreto

Citation if using this entry: Fallahi et al. (2023) New genera in 2010-2011. Mycosphere (in prep)

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1

Rocha et al. (2010) introduced Pseudoallosoma as a fungus associated with Coussapoa floccosae in Brazil’s tropical seasonal semideciduous montane forest. Pseudoallosoma nervisequens F.B. Rocha & R.W. Barreto is the only species of the genus that share similarity with Allosoma and Dictyonella in Saccardiaceae, however, some distinct features verified its placement in Myriangiaceae (Myriangiales). The proliferation of the colony of this fungus on the leaves gives them a mosaic appearance. The species produced superficial pseudothecia ascomata, which are solitary, globose to subglobose, and encircled with setae. Asci are bitunicate, subglobose, ellipsoid to obovoid, few per ascoma, and contain eight-spored. Ascospores are oval and inordinate. Young ascospores have a median septum and hyaline but become dark brown and often with oblique and longitudinal septa at maturity (Rocha et al. 2010).

Type species: Pseudoallosoma nervisequens F.B. Rocha, J.L. Bezerra & R.W. Barreto

Fig 1. Pseudoallosoma nervisequens (redrawn from Rocha et al. 2010). a Ascoma containing immature asci. b Bitunicate asci. c Ascospores at increasing degrees of maturity (left to right). Scale bars: a, b, c= 10 µm.


Rocha FB, Barreto RW, Bezerra JL, Neto JAAM. 2010- Foliar mycobiota of Coussapoa floccosa, a highly threatened tree of the Brazilian Atlantic forest. Mycologia 102, 1240-1252.

Entry by

Maryam Fallahi, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand.

(Edited by Kevin D Hyde and Ruvishika S. Jayawardena)

Published online 25 May 2023