Metacapnodium atro-olivaceus Berbee & Aliabadi 2026, comb. nov.

Metacapnodium atro-olivaceus (S. Hughes) Berbee & Aliabadi comb. nov. Fig. 5 Basionym. ≡ Capnobotrys atro-olivaceus S. Hughes, [as ‘ atro-olivacea ’], New Zealand J. Bot. 19 (2): 208 (1981). Specimen examined. New Zealand • South Island, Westland District, Granville Forest, Orwell Creek, on leaves of Nothofagus fusca, 2 Apr 1963, S. J. Hughes, from slides prepared by S. J. Hughes, from mixed collection, DAOM 106914 (Capnobotrys atro-olivaceus isotype). Description. The dark brown to black, velutinous subiculum of this specimen included abundant Metacapnodium australis. However, the several permanent slides associated with the specimen did contain M. atro-olivaceus. Mycelium of moniliform hyphae, olive-brown and densely verrucose throughout, warts coarse, prominent, dark olive-brown. Hyphae straight to curved, anastomosing, with lateral branching, tapering toward the ends, cells globose, as long as or broader than wide, to 16 μm wide, narrowing to 3.5–5 μm at the hyphal tips. Sexual form unknown. Asexual forms. Capnobotrys – Differentiated conidiophores not observed. Conidiogenous cells in irregularly arranged botryose clusters or in a unilateral series, brown and globose, elongating to become obpyriform during conidium formation. Conidia blastic, initially globose, then ovoid to ellipsoid, sometimes inequilateral, 11–13.5 × 7.5–9 µm, N = 8, Q = 1.5, olivaceous brown, smooth to verruculose, with one supramedial septum, slightly constricted at septum, proximal cell broader and slightly longer than the distal cell, with an inconspicuous scar that is located obliquely. Distal cells of conidia with apical wall thinning that is light olive brown in color. Capnophialophora – Phialides olive-brown with a verrucous, subspherical venter 5–6 μm in width, and a subcylindrical collarette up to 3.5 × 2.5–3.5 μm. No phialidic conidia observed. Hosts and Distribution. Hughes (1981) reported this species from New Zealand, in bark of woody hosts and on leaves of dicots in several plant families including Myrtaceae and Fagaceae. Notes. Metacapnodium atro-olivaceus can be distinguished from other species with similar capnobotrys forms by its dark olive brown color, prominent, dark-colored verrucae, the subcylindrical rather than funnel-shaped collarettes on its phialides, and as exemplified by Fig. 5 B, its mature hyphal cells are narrower than those of many other Metacapnodium species.