Distoseptispora rayongensis J. Yang & K.D. Hyde, in Hyde et al., Mycosphere 11(1): 579 (2020)
Index Fungorum number: IF554770
Holotype– MFLU 18-1045.
Saprobic on decaying twigs. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, dark brown to black, hairy, glistening. Mycelium partly superficial, partly immersed in the substratum, composed of brown, septate, branched hyphae. Conidiophores macronematous, mononematous, solitary, cylindrical, straight or slightly flexuous, septate, brown, smooth, paler towards the apex, 75–125 × 3.5–5.5 μm (x̅ = 100 × 4.5 μm, n = 10), rounded at apex. Conidiogenous cells integrated, terminal, monoblastic, cylindrical, brown. Conidia acrogenous, solitary, obclavate or obspathulate, rostrate, mostly 9–13-euseptate, rarely 14–15-septate, pale brown or pale olivaceous, becoming paler or hyaline towards the apex, guttulate, smooth, (36–)60–106(–120) × 9–14.5 μm (x̅ = 80 × 11.5 μm, n = 20), with a darkened scar at the base, sometimes with percurrent proliferation and forming another conidium from the conidial apex.
Culture characteristics: Conidia germinating on PDA within 24 h. Germ tubes produced from the conidial base. Colonies on PDA slow growing, reaching 5–10 mm diam. after one month at 25 °C in natural light, circular, aerial mycelium dense, brown; reverse dark brown, margin entire.
GenBank numbers: LSU: MH457137, SSU: MH457169, ITS: MH457172, tef1: MH463253, rpb2: MH463255 (MFLUCC 18-0415); LSU: MH457138, SSU: MH457170, ITS: MH457173, tef1: MH463254, rpb2: MH463256 (MFLUCC 18-0417).
Notes: Distoseptispora rayongensis resembles D. guttulata and D. suoluoensis in having conspicuous long conidiophores and euseptate conidia of similar size. However, D. rayongensis can be distinguished from D. guttulata and D. suoluoensis in conidial colour and shape. Percurrently elongating conidia are observed in D. rayongensis and D. suoluoensis (Hyde et al. 2020).
Distoseptispora rayongensis (MFLU 18-1045 holotype). a Colonies on the woody substrate. b Conidiophore. c Conidiogenous cell with conidium. d, e Conidia and conidiophores. f-k Conidia. l Germinated conidium. m, n Cultures, m from above, n from below. Scale bars: a = 100 μm, b, c, e-l = 30 μm, d = 50 μm.