Microsphaeropsis olivacea (Bonord.) Höhn., Hedwigia 59: 267 (1917)
Index Fungorum number: IF 438686, Facesoffungi number: FoF00400; Figs. 1 and 2

Saprobic on Sarothamnus scoparius twig. Sexual morph Ascomata 390–400×398–405μm (x=395× 400μm, n=5), superficial on the wood, densely crowded, in roundish to oval clusters, breaking through the bark, pyroid to globose, with flattened base, ostiole central and short, basally with some brown, thick-walled. Peridium 40–45μm (n=5), black, distinctly rough, thick, multi-layered, composed of cells of textura globulosa to angularis with red brown and smooth walls. Hamathecium comprising numerous, filiform, thinwalled, septate pseudoparaphyses, longer than the asci. Asci 105–142×12–14μm (x=130×13μm, n=5), 8-spored, cylindrical, bitunicate, thick-walled, apically rounded. Ascospores 25–29×10–12μm (x=26×10μm, n=5), muriform, ellipsoid, straight, both part of the spore +/-equal in size, end cells conical, immature spores hyaline, mature spores golden-brownish, septa constricted only in the centre, all stages without a gelatinous sheath. Asexual morph Coelomycetes species. Pycnidia 144 – 160μm (n=2), globose,whitewhen immature, pigmented gradually with age, brown when mature, with indistinct apical ostioles: Peridium 24–34μm (n=2), yellowish brown, of cells of textura angularis. Conidia 5.8–7(4) μm globose, smooth-walled, hyaline initially.

Culture characters: Ascospores germinating on PDA within 30 h and germ tubes produced from sides of the ascospores. Colonies growing on MEA, reaching 5 mm in 7 days at 15 °C, mycelium partly superficial, partly immersed, slightly effuse.

Material examined: GERMANY, on attached corticated Sarothamnus scoparius twig, 21 December 2013, R.K. Schumacher (MFLU 14–0819), living cultures, MFLUCC 14–0507. GenBank ITS: KR025859; LSU: KR025863.

Notes: The genus is similar to Coniothyrium but is differs rentiated by the mode of conidiogenous which is phialidic in Microsphaeropsis and holoblastic in Coniothyrium (Sutton 1980). Microsphaeropsis species produce ornamented conidia and are distinguishable from one another by conidial size and morphology. In the phylogenetic tree our sexual morph collection clustered with Microsphaeropsis olivacea and thus this is the first report of the sexual morph of this species.

Fig. 1 Microsphaeriopsis olivacea (MFLU 14–0819) a, b Ascomata c Section through of ascoma d Peridium e Setae f Pseudoparaphyses g–j Immature and mature asci. k–o Immature and mature ascospores p Germinating ascospore. Scale bars: a=500μm, b=200μm, c=100μm, d=50μm, e-j=30μm, k–o=10μm, p=20μm.

Fig. 2 Microsphaeriopsis olivaceae – asexual morph a. Germinating ascospore b. Culture from above c. Culture from below d. Induced the growth of asexual morph e. Conidiomata on toothpick f. Close up of conidiomata g. Section through conidioma h. Ostiole with immature conidiospores i Conidioma j Peridium k, l Arrangement of hyphae m, n Conidia. Scale bars: a=20μm, g=50μm, h-l=20μm, m=5μm, n=10μm.