Cystodermella rubrogranulosa J.A. Cooper & I. Saar

Saar, Irja, Cooper, Jerry A. & Trudell, Steven A., 2024, Two new species of Cystodermella and new combinations in Ripartitella (Agaricineae, incertae sedis) and Cystolepiota (Verrucosporaceae), Phytotaxa 658 (1), pp. 81-98 : 90-91

Cystodermella rubrogranulosa J.A. Cooper & I. Saar sp. nov. ( Figs. 5A–D , 4B )

MycoBank: MB 853105

Etymology:—'Rubrogranulosa' refers to the dark red-brown granulose surface of the pileus.

Diagnosis:—This species is characterised by its brownish red pileus, concolorous stipe with evanescent ring zone, broadly ellipsoid to ellipsoid basidiospores (av. 4.6 × 2.9 µm, Q av. = 1.6); and occurrence in Podocarpus and Nothofagus forests in New Zealand. It has somewhat longer basidiospores than other reddish brown Cystodermella species.

Holotype:— NEW ZEALAND. Auckland: Howick, Mangemangeroa Valley Walkway, 36.914593°S, 174.94483°E, 24 June 2017, Podocarpus totara forest, on ground, W. M. Daley JAC14642 ( PDD106521 ).

ITS sequence: GenBank: PP619106; MycoBank MB 10019172.

Description:— Pileus 10–25 mm broad, convex to plano-convex, subumbonate, dry, conspicuously spikygranulose, brownish red (8C8 to 9C8), darker in centre. Lamellae adnate with decurrent tooth, close, pale creamy to yellowish, edge entire; colours dark olivaceous grey in NH 4 OH. Stipe 20 × 2–6 mm, equal, dry, silky striate at top, with evanescent floccose-scaly ring zone, below coarsely granulose-floccose, concolorous with pileus on pallid background. Context white. Taste mealy (based on PDD96273). Smell not recorded. Spore deposit white.

Basidiospores (65 spores, three basidiomata, three collections) 4.0–5.5 × 2.4–3.7 µm, av. 4.4–4.7 × 2.7–3.0 µm, Q = 1.2–2.2, Q av. = 1.5–1.7, broadly ellipsoid to ellipsoid, rarely oblong, hyaline, inamyloid, metachromatic, cyanophilous ( Fig. 4B ). Basidia 18–27 × 4–7 µm, 4-spored, clavate, hyaline, inamyloid. Cystidia absent. Pileipellis formed by chains of sphaerocysts, 9–22 × 10–33 µm, globose to oblong, faintly rugulose, yellowish brown to dark brown in H 2 O, not darkening in KOH; arthroconidia absent in context under pileipellis. Stipitipellis composed of hyphae up to 12 µm broad, cylindric to inflated, covered by sphaerocysts, like those forming the pileipellis. Clamp connections present in all tissues.

Habitat:—solitary, on soil, in Podocarpus and Nothofagus forests. To date, known only from New Zealand.

Additional specimens examined:— NEW ZEALAND. Tasman: vic. Motueka, track to Riwaka Resurgence , Nothofagus solandri forest, on soil, 41.031°S, 172.899°E, 14 May 2004, F. Kell ( PDD94849 ) ; North Island: Rangitaiki Reserve, Taupo , frost flats, on soil, 743 m, 38.934°S, 176.433°E, 18 May 2011, J. A. Cooper JAC12023 ( PDD96273 ) .

Notes:—Morphologically the species is like other reddish brown Cystodermella species ( C. adnatifolia , C. cinnabarina , C. granulosa ; see Figs. 3B–F ), which are quite common and widely distributed, but not found in New Zealand, so far. See notes about the sizes of basidiospores from C. canadensis .

Figures

FIGURE 3. Species of Cystodermella. A. C. canadensis (WTU-F-073309, holotype). B. C. adnatifolia (TUF118417). C. C. cinnabarina (TUF106009, neotype). D. C. cinnabarina (TUF106012). E. C. granulosa (TUF120293, epitype). F. C. granulosa (TUF101314). Bar = 1 cm. Photos by: Steven A. Trudell (A), Vello Liiv (B–F).

FIGURE 4. Microscopic drawings (basidiospores, basidia) of the Cystodermella species described. A. C. canadensis (WTU-F-073309, holotype). B. C. rubrogranulosa (PDD106521, holotype). Bar = 10 µm. Drawings by: Irja Saar.

FIGURE 5. Cystodermella rubrogranulosa. A–B. PDD106521, holotype. C–D. PDD96273, paratype. Bar = 1 cm. Photos by: Jerry A. Cooper.