Entoloma avilanum (Dennis) E. Horak, Sydowia 28: 186. 1976

Karstedt, Fernanda, Bergemann, Sarah E., Gates, Genevieve, Ratkowsky, David, Cunha, Kelmer Martins & Capelari, Marina, 2024, Species of Entoloma (Entolomataceae) with cuboidal basidiospores from Brazil, Phytotaxa 654 (1), pp. 1-76 : 67-69

Entoloma avilanum (Dennis) E. Horak, Sydowia 28: 186. 1976 .

[≡ Nolanea avilana Dennis, Kew Bull. 15: 151. 1961; ≡ Inopilus avilanus (Dennis) Pegler, Kew Bull. Addit. Ser. 9: 350. 1983.]

Figs. 40a–b .

Description:— Pileus 1 cm diam., subcampanulate, strongly papillate, striate, colored flesh-pink, submembranaceous, context yellow. Lamellae adnate-sinuate, pale cinnamon, close. Stipe 20 × 1 mm, cylindrical, apex yellow, base ochraceous, glabrous, stuffed ( Dennis 1961).

Basidiospores cuboidal with slightly depressed sides and angles scarcely pronounced and rounded, with an obvious hilar appendix, 7.5–10 × 8.7–10 µm [xm = 8.56 (± 0.61) × 9.31 (± 0.64) µm, Q = 1–1.33, Qm = 1.09 (± 0.09), n = 20], thin-walled. Basidia clavate or cylindro-clavate, 43–60 × 12–15 µm (n = 6), hyaline, walls thin or thickened, 4-sterigmate. Margin of lamella difficult to see, the elements strongly agglutinated and partially collapsed. Cheilocystidia not recovered. Pleurocystidia and pseudocystidia not observed. Lamellar trama composed of subparallel hyphae, cylindrical or inflated, 3.7–11.2 µm diam. (n = 10), hyaline, thin-walled, septate, sub-hymenium not observed. Pileitrama not observed. Pileipellis a cutis of entangled, cylindrical prostrate hyphae, 5–13 µm diam. (n = 11), hyaline, thin-walled, septate. Stipitpellis and caulocystidia not observed. Clamp connections present. Refractive hyphae present.

Habitat:—Among bryophytes, on bark, at 2,000 m altitude ( Dennis 1961).

Distribution:—Reported from Guadalupe, Dominica (Pegler 1983) and Venezuela ( Dennis 1961).

Material examined:— VENEZUELA. El Ávila: Federal District, 17 August 1958, R. W.G. Dennis 1816 (Holotype, K) .

Comments:—The holotype of Entoloma avilanum consists of a single basidiome, with the pileus fragmented into four parts and the stipe separated from the pileus. At the base of the stipe, the presence of a bryophyte was observed. This species is characterized by the small basidiome, the flesh-pink cap and cuboidal basidiospores with slightly depressed sides and slightly rounded angles measuring 7.5–10 × 8.7–10 µm, plus cylindrical cheilocystidia (Horak 1975, Pegler 1983).

Entoloma avilanum has also been cited for the state of Pernambuco ( Coimbra et al. 2013). The material URM2273 consists of a single basidiome, small and brittle, not in good condition. In the morphological analysis, basidiospores measuring 7.5–8.7 × 7.5–8.7 µm were observed without the projections, 8.7–10 × 8.7–10 µm with the projections and 11.5–12.5 × 12–12.5 µm diagonally ( Fig. 40c–d ). Also observed were pigmented refractive hyphae and the presence of pseudocystidia, characteristics that differ from the holotype of E. avilanum , making it impossible to agree with the identification. The review of the two collections cited for Brazil (MC340 - Capelari 1989, URM2273 - Coimbra et al. 2013) excludes the citation of the species for Brazil. Attempts to obtain DNA from the above material were unsuccessful.

Figures

FIGURE 40. Entoloma avilanum (Dennis 1816): a. basidiospores; b. basidia. c–d. Entoloma sp. (URM2273): c. basidiospores; d. pseudocystidia. Scale: 10 µm.