Simplicillium pech-merlensis J. Leplat, 2021

Leplat, Johann, Francois, Alexandre & Bousta, Faisl, 2021, Simplicillium pech-merlensis, a new fungal species isolated from the air of the Pech-Merle show cave, Phytotaxa 521 (2), pp. 80-94 : 89

Simplicillium pech-merlensis J. Leplat , sp. nov. ( Fig. 5)

CBS: 147188

GenBank: MW 031272 ( ITS) , MW 031268 ( LSU) , MW 031740 ( SSU) , MW 033222 ( RPB1 ) , MW 033223 ( RPB2 ) , MW 033224 ( TEF1 -α) , MW 033221 (Tub)

Systematic position: Fungi, Dikarya, Ascomycota, Pezizomycotina, Sordariomycetes, Hypocreomycetidae, Hypocreales , Cordycipitaceae

Holotype:— FRANCE. Cabrerets , 44° 30’ 27″ N, 1° 38′ 40″ E, 07 October 2016. CBS 147188 . Isolated from the air of Pech-Merle cave.

Etymology: —The epithet pech-merlensis refers to the place where the species was isolated, namely Pech-Merle cave.

Colonies on PDA reaching 20–22 mm diam. after 10 days at 25 °C, cottony, low convex, margin entire to slightly undulated, white. Reverse white to pale yellow. No growth at 5 °C nor at 30 °C.

Colonies on MEA reaching 21–25 mm diam. after 10 days at 25 °C, cottony, low convex to raise with concave edge, margin entire, white. Reverse pale yellow to orangey. No growth at 5 °C nor at 30 °C.

Asexual morph: Hyphae hyaline and smooth-walled, Phialides 16–31 × 0.9–1.2 µm, mostly solitary, arising from prostrate hyphae, straight to slightly curved, tapering to the apex. Conidia 1-celled, smooth-walled, variable in size and shape, Microconidia 1.8–3 × 0.9–1.5 µm, adhering in globose slimy heads, subglobose to ellipsoidal. Macroconidia 5–8 × 1–1.6 µm, fusiform. Octahedral crystals absent.

a–b. Upper and reverse views of the culture on MEA (10 d at 25 °C). c–d. Upper and reverse views of the culture on PDA (10 d at 25 °C). e–f. Solitary phialides and microconidia that adhere to each other to form globose slimy heads. g. Microconidia and macroconidia. h. Solitary phialide and macroconidia. Scale bars: e–h = 10 µm.

Notes:— Simplicillium pech-merlensis seems morphologically close to S. calcicola Z.F. Zhang, F. Liu & L. Cai ,

S. album Z.F. Zhang & L. Cai and S. lamellicola . Furthermore, S. pech-merlensis , S. calcicola and S. album were isolated from the same habitat, i.e. karst cave. While S. pech-merlensis was isolated from the cave air, S. calcicola was isolated from the limestone ( Zhang et al. 2017) and S. album was isolated from the soil ( Zhang et al. 2020b). Each species produces both microconidia and macroconidia. Simplicillium lamellicola is distinguished from the three other species by the production of octahedral crystals. Simplicillium album produces larger macroconidia (8.0–11.0 (–13.0) × 2.0–3.5 μm) than S. pech-merlensis (5–8 × 1–1.6 µm) and S. calcicola (4.5–8.0 × 1.0–2.0 μm). Finally, Simplicillium pech-merlensis grows slower in culture media (20–22 mm diam after 10 days on PDA) than S. calcicola (34–38 mm diam after 10 days on PDA).