Gymnopus imbricatus, 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 : 37-39

Gymnopus imbricatus sp. nov.

Diagnosis.

Gymnopus imbricatus is distinguished from related New Zealand species by the smooth stipe, larger basidiospores, and imbricate habit.

Macromorphology.

Pileus 3-20 mm in diameter convex, cream to fawn, minutely felty, radially furrowed and striate towards the margin, margin fimbriate. Lamellae cream to creamy yellow, adnate. Lamellae present, in series of two: short/long. Stipe mostly eccentric, cartilaginous, to 3 × 0.5 mm, equal, umber to black, sometimes paler towards base, always entirely smooth. Stipe base insititious and usually associated with a thin 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 irregular clamped cutis of hyphae 4 µm diameter, without intra or extracellular pigmentation, terminal layer with gelatinised coralloid elements, to 2 µm wide, and occasional small finger-like trichodermal elements to 20 µm. Epidermal layer to 25 µm. Subepidermis of thick glassy-walled non-gelatinised smooth hyaline hyphae, weakly dextrinoid. Basidia clavate to 50 × 10 µm. Sterigmata to 5 µm, 4-spored. Basidioles to 50 × 6 µm cylindrical and tapered towards apex. Spores hyaline, lacrymoid 9.8 ± 1.2 × 5.1 ± 0.4 µm, Q = 1.9 ± 0.3 including apiculus. Cheilocystidia and pleurocystidia not observed. Stipitipellis a cutis of parallel brown hyphae, to 6 µm wide. Caulocystidia absent.

Habitat.

Forming imbricate colonies of dozens to hundreds of fruitbodies on bark and decorticate wood of dead branches and twigs, especially Kunzea and Leptospermum but occurs with other trees. Also occurs at the stem base of live trees.

Distribution.

Broadly distributed and common in both North and South Islands of New Zealand.

Etymology.

Imbricatus, pertaining to the often tiered and overlapping eccentrically stemmed caps.

Specimens examined.

New Zealand, North Island: PDD 80766, on bark of Beilschmedia tawa , Erua Forest, Taupo, collector J.A. Cooper (JAC9329), 4 April, 2005. PDD 87398, bark on dead branch of Nothofagus , Waiohine Gorge, Wairarapa, Collector J.A. Cooper (JAC10310), 10 May 2007. PDD 87410, dead stems of Ripogonum scandens , Waiohine Gorge, Wairarapa, Collector J.A. Cooper (JAC10322), 10 May 2007.

New Zealand, South Island: PDD 101753, dead branches of Nothofagus menziesii , Riwaka Resurgence, Nelson, Collector P.L. Leonard (PL25404), 10 April, 2006. PDD 96141, dead twigs of Kunzea ericoides , Mt Fyffe Track, Kaikoura, collector J.A. Cooper (JAC11734), 26 Feb. 2011. PDD 80154, dead log of Nothofagus menziesii , Lewis Pass, Buller, collector J.A. Cooper (JAC8287), 24 November, 2001. PDD 80157, on dead de-corticate log, Lyell Walkway, Nelson, collector J.A. Cooper (JAC80157), 25 November, 2001. PDD 87675, living stem of Fuchsia excorticata , Saddle Hill, Mid Canterbury, Collector J.A. Cooper (JAC10495), 22 May 2005. HolotypePDD 95489 (Figs 4 and 5), base of live trees of Kunzea ericoides , Kennedy’s Bush, Mid Canterbury, Collector J.A. Cooper (JAC11038), 24 May 2009. PDD 79799, bark of dead tree, Kennedy’s Bush, Mid Canterbury, Collector J.A. Cooper (JAC8921), 20 March 2004. PDD 87186, on bark of living tree of Kunzea ericoides , Hinewai Reserve, Akaroa, Mid Canterbury, Collector J.A. Cooper (JAC10089), 3 June 2006. PDD 87660, fallen log, Racemans Track, Silverstream Valley, Dunedin, Collector S. Dodd (JAC10816), 13 May 2008. PDD 87659, on dead twigs of Kunzea ericoides , Evansdale Glen, Dunedin, Collector P.R. Johnston (JAC10815), 12 May 2008.