Paracymostachys euphorbiae Crous, sp. nov.

Index Fungorum number: MB839507; Facesoffungi number: FoF

Etymology. Name refers to the host genus Euphorbia from which it was isolated.

Conidiophores macronematous, mononematous, erect, solitary or in groups, mostly unbranched, thick- and smooth- walled, hyaline to pale olivaceous brown, 70 –120 × 3 – 4 µm, 1– 2-septate, with 4 – 6 conidiogenous cells arranged in a cluster at apex. Conidiogenous cells phialidic, clavate to fusoid or elongate doliiform, hyaline, becoming olivaceous brown and verruculose with inconspicuous collarettes, 7–11 × 3 – 5 µm. Conidia in a mucoid droplet, aseptate, olivaceous brown to dark brown, smooth, becoming verruculose, thick-walled, guttulate, fusoid, with rounded apex and truncate base, (7.5 –)8 – 9(–10) × (3 –)3.5 – 4 µm; rarely subcylindrical, up to 17 µm Ger-minating conidia dark brown, verrucose, 1-septate (constricted at septum) with polar germination, 13 –17 × 6 –7 µm.

Culture characteristics — Colonies erumpent, spreading, surface folded, with moderate aerial mycelium and smooth, lobate margin, reaching 8 mm diam after 2 wk at 25 °C. On MEA surface saffron, margin umber, reverse umber; on PDA surface and reverse pale luteous; on OA surface iron-grey with buff margins.

Typus. SOUTH AFRICA, Mpumalanga, Mbombela, Lowveld Botanical Gar- den, on leaf litter of Euphorbia ingens (Euphorbiaceae), Nov. 2018, P.W. Crous, HPC 3140 (holotype CBS H-24495, culture ex-type CPC 38954 = CBS 146983, ITS, LSU, cmdA and rpb2 sequences GenBank MZ064419.1, MZ064476.1, MZ078163.1 and MZ078197.1).

Notes — Lombard et al. (2016) distinguished several genera in Stachybotryaceae. Paracymostachys can be distinguished from Cymostachys by having smooth, primarily unbranched conidiophores, and fusoid, rarely subcylindrical conidia. Para- cymostachys euphorbiae is distinct from Cymostachys species in not having fabiform to globose conidia. Furthermore, it is distinct from S. limonispora (conidia (6 –)6.5–7.5(– 9) × 3– 4 μm) in lacking limoniform conidia, and from S. phaeophialis (conidia ellipsoidal to fusoid) in having larger conidia ((6 –)6.5 –7.5(– 9) × 3 – 4 μm; Lombard et al. 2016).

Based on a megablast search of NCBIs GenBank nucleotide database, the closest hits using the ITS sequence had highest similarity to Stachybotrys dolichophialis (strain DAOM 227011, Colour illustrations. Mbombela, Lowveld Botanical Garden. Conidiophores with conidiogenous cells giving rise to conidia on SNA; conidia. Scale bars = 10 µm.

GenBank KU846734.1; Identities = 551/612 (90 %), 36 gaps (5 %)), Stachybotrys zeae (voucher HGUP 0143, GenBank KC305346.1; Identities = 546/611 (89 %), 37 gaps (6 %)) and Stachybotrys microspora (voucher HGUP 0120, GenBank KC305353.1; Identities = 545/ 610 (89 %), 36 gaps (5 %)).

Closest hits using the LSU sequence are Memnoniella echi- nata (strain CBS 216.32, GenBank MH866746.1; Identities = 852/863 (99 %), one gap (0 %)), Memnoniella humicola (strain CBS 463.74, GenBank NG_058217.1; Identities = 813 /825 (99 %), one gap (0 %)) and Stachybotrys limonispora (strain CBS 128809, GenBank MH876595.1; Identities = 848/ 863 (98 %), one gap (0 %)). Closest hits using the cmdA sequence had highest similarity to Stachybotrys phaeophialis (strain KAS 525, GenBank KU846632.1; Identities = 386 /466 (83 %), 11 gaps (2 %)), Stachybotrys dolichophialis (strain DAOM 227011, GenBank KU846628.1; Identities = 386 /466 (83 %), 11 gaps (2 %)) and Stachybotrys subsylvatica (strain CBS 126205, GenBank KU846634.1; Identities = 365 /441 (83 %), 19 gaps (4 %)). Closest hits using the rpb2 sequence had highest similarity to Striatibotrys rhabdospora (strain CBS 136395, GenBank KU846986.1; Identities = 620 /719 (86 %), no gaps), Striatibotrys eucylindrospora (strain CBS 203.61, GenBank KU846975.1; Identities = 630 / 732 (86 %), no gaps) and Stachybotrys microspora (voucher MFLU 18-2620, GenBank MW201479.1; Identities = 534 /621 (86 %), no gaps).

Species