Ophiobolus artemisiae (S. Konta, Bulgakov & K.D. Hyde) Wanas., Phookamsak & K.D. Hyde, comb. nov. Index Fungorum number: IF553914

Basionym: Entodesmium artemisiae S. Konta, Bulgakov& K.D. Hyde, in Ariyawansa et al., Fungal Diversity: https://doi.org/10.1007/s13225-015-0346-5, [79] (2015)

Holotype: Russia, Rostov Region, Shakhty City, Salty Hollow, stony steppe, dead stems of Artemisia campestris L., 3 June 2014, T. Bulgakov, T109 (MFLU 15-0007); ex type living culture, MFLUCC 14-1156

Saprobic on Artemisia. Sexual morph: Ascomata 300–350 μm high, 200–250 lm diam., semi-immersed, solitary, scattered or sometimes grouped beneath the host tissues, globose, dark brown to black, coriaceous, ostiolate. Papilla 70–120 m high, 70–90 μm diam., eccentric, papillate, black, smooth, fifilled with hyaline to pale brown cells. Peridium 10–15 μm wide at the base, 20–30 μm wide at the sides, thin, with 4–5 layers, outer layer heavily pigmented, thick-walled, comprising reddish to dark brown cells of textura angularis, inner layer composed of hyaline thin-walled cells of textura angularis. Hamathecium comprising numerous, 3–4 μm wide, fifilamentous, branched, septate, pseudoparaphyses, embedded in a mucilaginous matrix. Asci 120–160 9 13–15 μm (x = 145.4 9 13.8 μm, n = 20), 8-spored, bitunicate, fifissitunicate, cylindrical to cylindric-clavate, pedicellate, thick-walled at the apex, with an ocular chamber. Ascospores 80–140 9 3–5 μm (x = 117.4 9 3.9 μm, n = 30), tri-seriate, in parallel, scolecosporous, elongate cylindrical to cylindric-clavate, or fifiliform, tapered towards the lower cell, initially hyaline, becoming pale brown to yellowish brown at maturity, 15–20-septate, slightly constricted at the 8th or 9th septum, not constricted at the other septa, not breaking into part spores, smooth-walled. Asexual morph: Undetermined.

Material examined: RUSSIA, Rostov region, Shakhty city, Grushevka steppe slopes, near Grushevsky Pond, stony steppe on slope, 47.7234186, 40.255065, on stems of Artemisia austriaca Jacq. (Asteraceae), 12 May 2015, T.S. Bulgakov, T-0262 (MFLU 15-1966).

Notes: Ophiobolus artemisiae was introduced by Ariyawansa et al. (2015) as Entodesmium artemisiae. The species is typical of Entodesmium in having scolecosporous ascospores, but differs as its ascospores do not break into part spores and lack a swollen cell. Entodesmium artemisiae clustered with E. rude and thus the new species was introduced. In this study, E. artemisiae forms a well-resolved clade together with E. rude and Ophiobolus disseminans. Therefore, E. artemisiae is synonymized under Ophiobolus. Our strain (MFLU 15-1966) clusters with the type strain of Entodesmium artemisiae with strong support (100% ML, 100% MP and 1.00 PP). The TEF1-a pairwise comparison shows that MFLU 15-1966 differs from the type strain in seven base positions and is almost the same in ITS sequence data. Although, MFLU 15-1966 differs from the type species in its dimensions of ascomata, asci and ascospores, it is typical of Ophiobolus artemisiae in morphology. Hence, our isolate is identifified as O.artemisiae and a new record on Artemisia austriaca is reported.

Hosts: Artemisia campestris L., Artemisia austriaca Jacq. (Asteraceae)

Distribution: Russia

FIG Ophiobolus artemisiae (MFLU 15-1966). a, b Ascomata on host substrate. c Section of ascoma. d Peridium. e Pseudoparaphyses. f, g Asci. h–k Ascospores. Scale bars: a = 1 mm, b = 200 μm, c = 100 μm, d, f–l = 20 μm, e = 10 μm