Gymnopus hakaroa, Cooper, Jerry A. & Leonard, Pat L., 2013

Cooper, Jerry A. & Leonard, Pat L., 2013, Three new species of foetid Gymnopus in New Zealand, MycoKeys 7, pp. 31-44 : 39-41

Gymnopus hakaroa sp. nov.

Diagnosis.

Gymnopus hakaroa is distinguished from Gymnopus ceraceicola by smaller stature and a pruinose stipe lacking fascicles of agglutinate caulocystidia. It is distinguished from Gymnopus imbricatus by non-imbricate growth, a consistently central stipe, and smaller basidiospores.

Macromorphology.

Pileus 3-10 mm diam. convex, rusty tawny to umber, minutely felty, weakly radially furrowed and striate towards the margin. Lamella cream to yellow, waxy. Lamellae present, in series of three: intercalated short/long/short. Stipe central, cartilaginous, to 5 × 0.6 mm, equal, umber to black, paler towards base, smooth to minutely pruinose. Stipe base insititious and always associated with an obvious waxy to chalky cream layer of partially gelatinised hyphae covering the substrate, usually green with algal cells. Fruitbodies with garlic/rotten cabbage smell, especially when crushed.

Micromorphology.

Pileipellis a partially gelatinised radially arranged clamped cutis of smooth hyphae to 3 µm in diameter, with brown extra-cellular encrustation. Epidermal layer to 80 µm. Subepidermis of thick glassy-walled non-gelatinised smooth hyaline hyphae, to 3 µm in diameter, weakly dextrinoid. Basidia clavate to 40 × 8 µm. Sterigmata to 7 µm, 2-4-spored. Basidioles cylindrical and tapered towards apex 40 × 6 µm. Spores hyaline, lacrymoid 8.3 ± 1 × 4.8 ± 0.3 µm, including apiculus, Q = 1.7 ± 0.2. Cheilocystidia and pleurocystidia not observed. Stipitipellis a cutis of hyaline to pale brown hyphae, to 5 µm wide. Stipe without caulocystidia.

Habitat.

Forming imbricate colonies of dozens to hundreds of fruitbodies on decorticate dead wood.

Distribution.

Currently Gymnopus hakaroa is only known from a single location on the Canterbury Port Hills in the South Island of New Zealand.

Etymology.

Hakaroa, a Maori name for the Bank’s Peninsula region of New Zealand.

Notes.

Sequence data (Fig. 1) indicates a close phylogenetic relationship to Gymnopus imbricatus but there are consistent and substantial morphological differences.

Specimens examined.

New Zealand, South Island: Holotype PDD 87315 (Figs 6 and 7) on dead log, Kennedys Bush Reserve, Port Hills, Mid Canterbury, Collector J.A. Cooper (JAC10225), 11 Feb. 2007. PDD 81086 (Fig. 8), on dead wood of Kunzea ericoides , Kennedys Bush Reserve, Port Hills, Mid Canterbury, Collector J.A. Cooper (JAC9585), 23 July, 2007. PDD 96390, on dead decorticate log of Melicytus ramiflorus , Kennedys Bush Reserve, Port Hills, Mid Canterbury, Collector J.A. Cooper (JAC11301), 17 April, 2010.