Mycena aff. holoporphyra (Berkeley & M.A. Curtis 1869: 284) Singer (1962b: 64)

Cooper, Alexandra C., Desjardin, Dennis E. & Perry, Brian A., 2018, The genus Mycena (Basidiomycota, Agaricales, Mycenaceae) and allied genera from Republic of São Tomé and Príncipe, West Africa, Phytotaxa 383 (1), pp. 1-47 : 12-13

2. Mycena aff. holoporphyra (Berkeley & M.A. Curtis 1869: 284) Singer (1962b: 64) . ( Fig. 6 )

Description:— Pileus 11–19 mm diam, broadly convex to campanulate with raised disc, becoming broadly convex to planar, margin pellucid-reticulate to tesselate, split in age; surface moist, glabrous, hygrophanous, dull, disc dark brown (7–8F4–8) with margin pale reddish brown (8E4). Lamellae horizontal, adnate with a decurrent tooth to arcuate, distant to subdistant with 1–2 series of lamellulae, subporoid to reticulate with shorter cross lamellae, greyish brown (8D–E3); edge concolorous. Stipe 20–30 × 1.5–2 mm, central, terete or flattened towards base, hollow; surface moist to dry, glabrous, dull, dark brown (8F4–5). Odour and taste not recorded. Bioluminescence undetected.

Basidiospores 6.4–8.0 × 4.0–4.8 μm [x m = 7.36 ± 0.49 × 4.28 ± 0.39 μm, Q = 1.5–2, Q m = 1.73 ± 0.17, n = 20, s = 1], ellipsoid, smooth, hyaline, amyloid, thin-walled. Basidia 20–25 × 7.2–8.0 μm, clavate, hyaline, inamyloid, thin-walled, 4-spored, rarely 2-spored, sterigmata up to 8.0 μm long. Basidioles clavate. Lamellar edge sterile. Cheilocystidia 34–45 × 8.0–8.8 μm, fusiform to lageniform, hyaline, inamyloid, thin-walled. Pleurocystidia absent. Pileipellis a cutis; hyphae 1.6–4.8 μm diam, repent, cylindrical, smooth or sparsely diverticulate, hyaline, inamyloid, thin-walled, non-gelatinous; diverticula 1–2 × 0.5–1 μm, cylindrical. Hypodermium composed of inflated cells up to 19.2 μm diam, globose to ovoid, smooth, hyaline, dextrinoid, thin-walled. Lamellar trama regular; hyphae 2.5–8.8 μm diam, hyaline, dextrinoid, non-gelatinous, thin-walled. Stipitipellis a cutis; cortical hyphae 1.6–6.4 μm diam, parallel, cylindrical, hyaline, dextrinoid, thin-walled, non-gelatinous; medullary hyphae 8–20 μm diam, smooth, dextrinoid, thin-walled. Caulocystidia common at apex, scattered elsewhere, 30–67 × 5.6–11.2 μm, subcylindrical to fusoid, occasionally subcapitate or with one or more broad knobs, hyaline, inamyloid, thin-walled. Clamp connections present in all tissues.

Habitat and known distribution:—Solitary in leaf mulch or soil in primary forest. ( São Tomé).

Material examined:—AFRICA. São Tomé, Macambrara radio antenna area, elevation 1300 m, N00˚16.557’, E06˚36.326’, 25 April 2008, D.E. Desjardin, DED 8334 (SFSU).

Notes:— Mycena aff. holoporphyra is characterized by a convex to campanulate, reticulate-tesselate, dark brown pileus, arcuate, subporoid to reticulate, greyish brown lamellae, a dark brown stipe, basidiospores with mean 7.4 × 4.3 μm, fusiform to lageniform cheilocystidia, no pleurocystidia, a cutis-type pileipellis of smooth or sparsely diverticulate, non-gelatinous hyphae, subcylindrical to fusiform caulocystidia, and growth in leaf mulch in primary forest. In combination, these features indicate placement in sect. Calodontes .

The New World M. holoporphyra (type locality: Cuba) differs from the São Tomé specimen in forming deep violaceous to vinaceous basidiomata and growing on wood (Pegler 1983). In all other macro- and micromorphological features they are indistinguishable. Until more material becomes available for the dark brown form described herein, we recognize it as Mycena aff. holoporphyra .

Pairwise comparisons of aligned, overlapping ITS sequences of the São Tomé specimen (DED 8334) with the top ten BLAST results show 93.9–94.3% similarity to several sequences of M. pearsoniana (JN182201, FN394615, FN394616, FN394612), a member of sect. Calodontes . No sequences of New World M. holoporphyra are available for comparison. In the ITS phylogeny ( Fig. 2), Mycena aff. holoporphyra falls into the clade with other members of sect. Calodontes , sister to the bioluminescent Malaysian M. cahaya .

Figures

FIGURE 6. Mycena aff. holoporphyra (DED 8334). a. Basidiospores. b. Basidia. c. Cheilocystidia. d. Pileipellis hyphae. e. Caulocystidia. Scale bar = 10 μm.