Entoloma vinososquamulosum 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 : 60

Entoloma vinososquamulosum Karstedt & Capelari sp. nov.

Figs. 29 , 32a–c , 35f–g

MB 838601

Etymology:— Vinososquamulosum refers to the vinaceous coloration of the scales on the surface of the pileus.

Diagnosis:— Entoloma vinososquamulosum is characterized by the combination of a convex-papillate pileus with obvious vinaceous scales, and a stipe with yellowish beige to slightly vinaceous apex.

Type:— BRAZIL. Rio Grande Do Sul: Aparados da Serra National Park, Vertex Trail , 19 January 2011, F. Karstedt FK1745 (Holotype, SP) .

Description: Pileus 14 mm diam., strongly convex with an obvious papilla, whitish beige with vinaceous scales, opaque, slightly translucent-striate, not hygrophanous, surface fibrillose scaly, center of pileus punctate-squamulose, margin of pileus slightly irregular. Pileus context thin, white. Lamellae adnexed-sinuate, ventricose (<2 mm at deepest part), close, yellowish creamy white, with two series of lamellulae, margins irregular. Stipe 43 × 2–3 mm, attenuated upwards, centrally attached, apex yellowish beige to slightly vinaceous towards the base, longitudinally striate and twisted, slightly fibrillose, fibrous, hollow, with white basal tomentum. Stipe context white. Odor and taste not observed. Spore print not observed.

Basidiospores cuboidal with a hilar appendix present, 7.5–8.7(–10) × 7.5–8.7(–10) µm [xm = 8.12 (± 0.75) × 8.68 (± 0.49) µm, Q = 1–1.16, Qm = 1.07 (± 0.85), n = 20], thin-walled. Basidia narrowly clavate, 42–54 × 10–14 µm (n = 20), hyaline, thin-walled, 4-sterigmate. Cheilocystidia along the entire lamellar margin, cylindrical, cylindro-clavate, clavate, irregular or hyphoid, sometimes branched, sometimes slightly collapsed, 18–77 × 5–12.5 µm (n = 20), hyaline or slightly straw yellow, thin-walled. Pleurocystidia and pseudocystidia absent. Lamellar trama of subparallel, cylindrical or broadly cylindrical hyphae, 3.7–12.5 µm diam. (n = 20), hyaline, thin-walled, septa rare; sub-hymenium branched. Pileitrama composed of radially entangled, cylindrical or broadly cylindrical hyphae, 3.7– 19 µm diam. (n = 20), hyaline, thin-walled, septate. Pileipellis a cutis of entangled prostrate hyphae in transition to a trichoderm, cylindrical or slightly inflated, 3.7–8.7 µm diam. (n = 20), hyaline or with straw yellow intracellular pigment, thin-walled; terminal hyphae narrowly clavate or cylindrical with a rounded apex. Stipitipellis a cutis, with cylindrical hyphae, 2.5–8.7 µm diam. (n = 20), hyaline or with straw yellow intracellular pigment, thin-walled, septate. Caulocystidia dispersed, solitary or in small groups, prostrate or anticlinal, clavate or narrowly clavate, hyaline or with straw yellow intracellular pigment, thin-walled. Clamp connections present. Refractive hyphae present.

Habitat:—Solitary, in soil with litter and roots, in the Atlantic Forest biome.

Distribution:—This species is known only from the type collection from Rio Grande do Sul, Brazil.

Comments:— Entoloma vinososquamulosum differs from the similar species E. arenicola and E. voltavelhense in having obvious scales and a vinaceous color beneath a pale surface, and also in having cuboidal basidiospores without elongated angles or depressed faces and a cutis-type pileipellis with entangled prostrate hyphae with transition to a trichoderm. In the phylogenetic analysis this species is not related to either E. arenicola or E. voltavelhense ; it is a distinct species maybe weakly related to the /Psittacini subclade.

Figures

FIGURE 29. Entoloma vinososquamulosum (FK1745): a. basidiospores; b. basidia; c. cheilocystidia. Scale: 10 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.