Vialaea Sacc., Bull. Soc. mycol. Fr. 12: 66 (1896)
Xylariomycetidae, Amphisphaeriales, Vialaeaceae, Vialaea
Parasitic or saprobic on dead plant matter. Sexual morph: Pseudostroma appears as ellipsoidal, black dots slightly raised from substrate, thick around the upper part of the ascomata. Ascomata perithecial, solitary or aggregates, immersed, globose, subglobose to ellipsoidal, coriaceous, black to brown, papillate, ostiolate with periphyses. Papilla long, sometimes distal end curving towards the substrate, periphysate. Peridium thick, composed of outer, dark-brown, thick-walled cells of textura angularis and inner, hyaline, thick-walled cells of textura angularis. Paraphyses filiform, rarely branched, septate, hyaline, sometimes apex slightly swollen. Asci 8-spored, unitunicate, cylindrical, sometimes tapering towards the apex or base, short-stalked or sessile, thin-walled except apex, apex obtuse or truncate, apical ring subconical or subapical, J+. Ascospores biseriate, triseriate to fasciculate, sometimes weakly helically coiled, hyaline, strongly isthmoid, ends fusiform to rhombic, apical portion sometimes slightly larger than the basal part, 1–3-septate, smooth-walled. Asexual morph: Ceolomycetous. Conidiomata pycnidia, superficial, solitary, scattered, globose, with slimy, shining spore mass and basal mycelium forming thick, black strands. Conidiophores erect, branched, septate, hyaline. Conidiogenous cells phialidic, discrete or in small whorls, lageniform to cylindrical, hyaline. Conidia oblong to ellipsoidal, 1-celled, hyaline smooth, with truncate abscission scar (adapted from Senanayake et al. 2014).
Type species: Vialaea insculpta (Fr.) Sacc., Bull. Soc. mycol. Fr. 12: 66 (1896)
Notes: Vialaea comprises Vialaea bambusae, V. insculpta, V. minutella and V. mangiferae (Shoemaker et al. 2013, Senanayake et al. 2014, Index Fungorum 2020). Vialaea insculpta was reported from twigs and leaf veins of Ilex aquifolium grown commercially as ornamental plants. This species is reported only from in Europe and North America (Atkinson & Trelawny 1962, Shaw 1973).
Species illustrated in this entry:
Vialaea insculpta (Fr.) Sacc.
Vialaea mangiferae Senan. & K.D. Hyde
Atkinson RG, Trelawny JG. 1962 – A spore trap to study sporulation in tree canker diseases. Canadian Plant Disease Survey 42, 151–154
Index Fungorum. 2020 – http://www.indexfungorum.org/Names/Names.asp
Senanayake IC, Maharachchikumbura SSN, Mortimer PE, Xu J et al. 2014 – Vialaeaceae; introducing a novel species Vialaea mangiferae. Sydowia 66, 203–216
Shaw CG. 1973 – Host fungus index for the Pacific Northwest - I. Hosts. Bulletin, Washington Agricultural Experiment Station 765, 1–121
Shoemaker RA, Hambleton S, Liu M. 2013 – Vialaea insculpta revisited. North American Fungi 8, 1–13