Requienella fraxini

Requienella fraxini Jaklitsch & Voglmayr, Persoonia 37: 95. 2016.

MycoBank MB814828

AUTHORS: Olariaga, I. & Tello, S.
Taxonomic classification

phy Ascomycota

sbp Pezizomycotina

cls Sordariomycetes

sbc Xylarioomycetidae

ord Xyariales

fam Requienellaceae

gen Requienella

sp Requienella fraxini


Ascomata perithecioid, growing isolately or in small groups of 2-5 ascomata, immersed, 0.51 mm high, conical and with a rounded base, with an erumpent apical beak, conical and more or less acute, black and shiny, often surrounded by a white disc. Peridium composed of pseudoparenquimatic cells.  Ascospores ellipsoid to oblong, initially hyaline and aseptate, later pale yellow and septate, in the end brown and with 3(5) transversal pseudosepta, thick-walled and with broad lumen, smooth or slightly ornamented, 25-32 × 9–12 µm. Asci oblong to clavate, bitunicate, fissitunicate, thick-walled, with a slightly refractive and concophilous ocular chamber, (4)8-spored arranged uni- or biseriately, pleurorrhynchous, 150-200 × 20-30 µm.  Hamathecium composed of unbranched paraphyses, apically free, with small refractive guttules when vital, 2-5 µm broad.

Ecology and distribution: Species that grows strictly on thick bark of ancient Fraxinus trees. Probably not rare in the central and south areas of the Iberian Peninsula where pollard Fraxinus angustifolia trees are rather common, but records of R. fraxini are still scarce.

References in our territory


Specimens in scientific collections

Especimen de referencia marcado en negrita

CR: ARAN-Fungi 14123 (det. H. Voglmayr)

J: S.T.19111701 (det. S. Tello, herb. S. Tello)

M: ARAN-Fungi 14143 (det. I. Olariaga)


Sequences in public databases obtained from material collected in our territory



Ascomata on bark of Fraxinus angustifolia (ARAN-Fungi 14123). Photographs: Ibai Olariaga.

S.T.19111701. A, b) Ascomata on bark of Fraxinus angustifolia (ARAN-Fungi 14123); c,d ) Ascoma sections. Photographs: Salvador Tello.

S.T.19111701. A) Hymenium showing 8-spored asci; b) Section of perithecial wall; c) Hamathecium; d) Asci SDS Congo Red, e) Ascospores. Photographs: Salvador Tello.

Asci and hamathecium (ARAN-Fungi 14123). Photograph: Ibai Olariaga.

Ascus in water (ARAN-Fungi 14123). Photograph: Ibai Olariaga.

Asci in SDS Congo Red (ARAN-Fungi 14123). Photograph: Ibai Olariaga.

Ascospores in water (ARAN-Fungi 14123). Photograph: Ibai Olariaga.

How to cite this sheet:

Olariaga I. & Tello S. 2020. Requienella fraxini Jaklitsch & Voglmayr. Fichas SIM (updated on 17-V-2020)