Entoloma voltavelhense Karstedt & Capelari

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 : 63-67

Entoloma voltavelhense Karstedt & Capelari sp. nov.

Figs. 31 , 32h–j , 35c–e

MB 852110

Etymology:— Voltavelhense refers to Volta Velha Private Natural Heritage Reserve, one of the localities at which the species was collected.

Diagnosis:—This species is characterized by the combination of a vinaceous pink pileus, cuboidal basidiospores with slightly elongated angles, cylindrical to clavate cheilocystidia, clamp connections and the absence of refractive hyphae.

Type:— BRAZIL. Rio De Janeiro: Teresópolis, Serra dos Órgãos National Park , Teresópolis Headquarters , Postcard Trail , 5 January 2011, F. Karstedt et al. FK1694 (Holotype, SP) .

Description:— Pileus 8–23 mm diam., conical-papillate, slightly conical-convex, convex, plano-convex or applanate, opaque, vinaceous pink, vinaceous, sometimes with center brownish vinaceous, then paler to beige at margin, not hygrophanous, surface adpressed-fibrillose to slightly fibrillose-squamulose, margin smooth, dentate or irregular. Pileus context thin, white. Lamellae sinuate or adnexed-sinuate, sometimes slightly reticulated, pinkish beige, distant with two tiers of lamellulae, margins entire or slightly irregular. Stipe 25–60 × 1–4 mm, cylindrical or attenuated upwards, centrally attached or slightly eccentric, slightly pinkish brown-beige with beige apex, or apex slightly brownish with a whitish base, or wholly white, silky, covered by thin adpressed fibrils, apex slightly pruinous, glabrous, smooth, fibrillose, hollow, with white basal tomentum, rhizoids white. Stipe context white. Odor and taste not observed. Spore print not observed.

Basidiospores cuboidal with slightly elongated angles, with a hilar appendix present, excluding the projections 7–8.7 × 7.5–8.7 µm [xm = 7.63 (± 0.49) × 8.13 (± 0.58) µm, Q = 1–1.16, Qm = 1.07 (± 0.07), n = 28/3], 7.5– including the projections 10.5 × 8.7–10 µm [xm = 8.93 (± 0.60) × 9.47 (± 0.64) µm, Q = 1–1.14(–1.33), Qm = 1.06 (± 0.08), n = 34/3] and diagonally 9–12.5 × 10–13.7 µm [xm = 10.84 (± 0.83) × 11.63 (± 0.79) µm, Q = 1–1.25, Qm = 1.08 (± 0.07), n = 34/3], thin-walled. Basidia clavate or cylindro-clavate, (37–)42–62 × 11–14(–15) µm (n = 43), hyaline, thin-walled, rarely thickened, sub-hymenium branched, 4-sterigmate. Cheilocystidia covering the entire lamella margin, cylindrical, cylindro-clavate, clavate, hyphoid or irregular, sometimes branched, 27–100 × 5–11.2 µm (n = 50), hyaline or light straw yellow, thin-walled, rarely thickened. Pleurocystidia and pseudocystidia absent. Lamellar trama composed of subparallel hyphae, cylindrical or broadly cylindrical, sometimes branched, 3.7–24 µm diam. (n = 59/3), hyaline, thin-walled, rarely septate, sub-hymenium branched. Pileitrama composed of radially entangled, cylindrical or broadly cylindrical hyphae, 6.5–21 µm diam. (n = 20), hyaline, thin-walled, septate. Pileipellis a cutis formed by prostrate, cylindrical hyphae, 6.2–11.2 µm diam. (n = 53/5), hyaline or with straw yellow intracellular pigment, thin-walled, terminal hyphae prostrate or anticlinal, cylindrical, cylindro-clavate or clavate, with rounded apex, hyaline or with straw yellow intracellular pigment, thin-walled. Stipitipellis a cutis of prostrate, cylindrical hyphae, 3.7–6.5 µm diam. (n = 10), hyaline or with straw yellow intracellular pigment, thin-walled, septate. Caulocystidia dispersed, prostrate or slightly anticlinical, cylindrical or cylindro-clavate, 44–100 × 7.5–14 µm (n = 10), hyaline or straw yellow, thin-walled. Clamp connections present. Refractive hyphae absent. Oleiferous hyphae present.

Habitat:—Solitary or gregarious, in sandy soil with litter, in restinga forest, in the Atlantic Forest biome.

Distribution:—Occurs in the states of Rio de Janeiro and Santa Catarina.

Additional material examined: BRAZIL. Santa Catarina: Itapoá, Volta Velha Private Natural Heritage Reserve, Glasshouse Trail , 10 December 2011, F. Karstedt et al. FK2105 ( FLOR); Trilha do Sambaqui , 11 December 2011, F. Karstedt et al. FK2118 ( FLOR) .

Comments:— E. voltavelhense is phylogenetically and morphologically close to E.arenicola but in E. voltavelhense the fibrils of the pileus thin towards the margin, while in E. arenicola they cover the whole the surface of the pileus. In addition, refractive hyphae are present in E. arenicola but absent in E. voltavelhense . Also, the angles of the basidiospores in E. voltavelhense are more elongated than in E. arenicola .

Excluded species

The types of Entoloma avilanum (Dennis) E. Horak (1976:186) and E. kamerunense (Bres.) E. Horak (1977:292) described from Venezuela and Cameroon, respectively, were compared with Brazilian collections labelled with these names and it was concluded that the former are not the same species as those that occur in Brazil.

Figures

FIGURE 31. Entoloma voltavelhense: a–c. basidiospores: a. FK2118; b. FK2105; c. FK1694; d. basidia (FK2105); e–f. cheilocystidia: e. FK2105; f. FK1694; g. pileipellis (FK2118). Scales: a–f: 10 µm, g: 20 µm.

FIGURE 32. Microphotography of basidiospores in electron microscopy: a–c. E. vinososquamulosum (FK1745); d–g. E. viscaurantium (Singer B11442); h–j. E. voltavelhense (FK1694). Scale: 5 µm.

FIGURE 35. Basidiomas: a–b. Entoloma arenicola: a. FK1811; b. FK2089; c–e. E. voltavelhense: c. FK1694; d–e. FK2118; f–g. E. vinososquamulosum (FK1745). Photos: F. Karstedt. Scale: 1 cm.