Cystodermella canadensis I. Saar & S.A. Trudell

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 : 88-90

Cystodermella canadensis I. Saar & S.A. Trudell sp. nov. ( Figs. 3A , 4A )

MycoBank: MB 853104

Etymology:—'Canadensis' refers to the Canadian origin of the type specimen.

Diagnosis:—Characterised by pale brownish orange to brownish tones of the pileus, a concolorous stipe with a white evanescent ring zone; broadly ellipsoid to ellipsoid basidiospores (av. 4.6 × 3.2 µm, Q av. = 1.4); and occurrence in coniferous forests in western North America. It has somewhat larger and rounder basidiospores than the similarly brown-coloured Cystodermella granulosa .

Holotype:— CANADA. British Columbia: Sumallo Grove, Manning Provincial Park, in conifer forest with Pseudotsuga menziesii , Picea engelmannii , Tsuga heterophylla , Pinus contorta , Populus trichocarpa , and Thuja plicata , on gravelly soil, 49.2095°N, 121.0792°W, 13 September 2008, S.A. Trudell SAT-08-257-22 (WTU-F-073309; TUF141093, isotype).

ITS sequences of holotype and isotype, GenBank/ UNITE: MZ054338 ; PP575896/ UDB07674167 ; MycoBank MB 10019171 .

Description:— Pileus 20–50 mm broad, convex to plano-convex, slightly umbonate, dry, conspicuously granulose, pale brownish orange, light brown to brown (6C7–6 to 6D–E7), margin appendiculate with white veil remnants. Lamellae adnexed, close, white to whitish, edge entire. Stipe 20–40 × 3.5–10 mm, equal, dry, silky striate at top, with evanescent floccose-scaly ring zone (white remnants of partial veil), below coarsely granulose-floccose, concolorous with pileus on pallid background, base somewhat swollen. Context white. Taste mild. Smell not distinctive. Spore deposit not taken, presumably white or whitish.

Basidiospores (94 spores, three basidiomata, two collections) 3.7–5.8 × 2.5–3.9 µm, av. 4.4–4.7 × 3.0–3.3 µm, Q = 1.1–1.9, Q av. = 1.4–1.5, broadly ellipsoid to ellipsoid, rarely oblong, hyaline, inamyloid ( Fig. 4A ). Basidia 20–30 × 4–7 µm, 4-spored, clavate, hyaline, inamyloid, metachromatic, cyanophilous. Cystidia absent. Pileipellis formed by chains of sphaerocysts, 20–54 × 13–37 µm, globose to oblong, faintly rugulose, hyaline to yellowish brown in H 2 O, not darkening in KOH. Arthroconidia absent in context under pileipellis. Stipitipellis composed of hyphae up to 9 µm broad, cylindric to inflated, covered by sphaerocysts, like those forming the pileipellis. Clamp connections present in all tissues.

Habitat:—Gregarious, on soil, in coniferous forest ( Pseudotsuga sp. , Picea sp. , Pinus sp. , Thuja sp. ) with some Populus sp. Known from two localities in North America: western Canada and southwestern USA.

Additional specimens examined:— USA. New Mexico: Taos County, Red River, Highway 38 between Elephant Rock Campground and molybdenum mine, under Pseudotsuga menziesii , Populus tremuloides , Picea sp. , Pinus ponderosa , P. monticola , on soil, 8700 feet, 36.7084°N, 105.4493°W, 4 September 1993, R.E. Halling 7104 (NY!). ITS sequence: GenBank/ UNITE: PP575897/ UDB023420.

Notes:—Morphologically resembling other Cystodermella species (see Figs. 3B–F ), found in North America, sharing the same pileus and stipe colour with C. granulosa , but its basidiospores are somewhat larger and rounder: C. adnatifolia (av. 4.3 × 2.8 µm, Q av. = 1.5), C. cinnabarina (av. 4.0 × 2.6 µm, Q av. = 1.5) and C. granulosa (av. 4.1 × 2.6 µm, Q av. = 1.6) ( Saar 2016). Cystodermella cinnabarina is easily recognized by its narrowly lageniform cystidia, with a crystal-covered spear-like apex.

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.