Entoloma mocamboense 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 : 50-51

Entoloma mocamboense Karstedt & Capelari , sp. nov.

Figs. 22 , 38f

MB 838595

Etymology:— Mocamboense refers to the Mocambo Reserve where the species was collected.

Diagnosis:— Entoloma mocambaense is characterized by the combination of a brownish beige-pink delicate basidiome with a strongly translucent-striate pileus, the presence of clavate cheilocystidia, and cuboidal basidiospores with scarcely elongated angles.

Type:— BRAZIL. Pará: Belém, Mocambo Reserve , 22 February 2011, F. Karstedt & E. Castro FK1899 (Holotype, SP) .

Description:— Pileus 13 mm diam., broadly conical, strongly translucent-striate, brownish beige-pink with brownish center and striae, hygrophanous, slightly adpressed-fibrillose, margin irregular and radially torn. Pileus context thin. Lamellae sinuate, ventricose, pink, distant, with lamellulae in two tiers, faces smooth, margins irregular, serrate. Stipe 45 × 1–2 mm, cylindrical, centrally attached, pinkish beige, slightly translucent, smooth, glabrous, adpressed-fibrillose with a silky aspect, hollow, with white basal tomentum. Stipe context translucent. Odor and taste not observed. Spore print pink, seen at the apex of the stipe.

Basidiospores cuboidal with or without scarcely elongated angles, 4-angled in profile view, excluding the projections 6.2–8.7 × 7–8.7 µm [xm = 7.28 (± 0.61) × 7.85 (± 0.61) µm, Q = 1–1.4, Qm = 1.08 (± 0.11), n = 20], including the projections 7.5–10 × 7.5–11.2 µm [xm = 8.3 (± 2.5) × 9.14 (± 1) µm, Q = 1–1.33, Qm = 1.1 (± 0.11), n = 20], and diagonally 8.7–11.2 × 10–12.5 µm [xm = 10.37 (± 1) × 11 (± 1) µm, Q = 1–1.43, Qm = 1.06 (± 0.06), n = 20], thin-walled. Basidia clavate, 29–44 × 10–12.5 µm (n = 9), hyaline, thin-walled, 4-sterigmate. Cheilocystidia cylindrical, cylindro-clavate or clavate, 25–70 × 5–19 µm (n = 10), hyaline, thin-walled. Pleurocystidia and pseudocystidia absent. Lamellar trama of parallel, cylindrical or broadly cylindrical hyphae, 3.7–21 µm diam. (n = 21), hyaline, thin-walled, septa distant; sub-hymenium branched. Pileitrama not observed. Pileipellis formed by prostrate hyphae, cylindrical, 2.5–13.7 µm diam. (n = 20), hyaline, thin-walled, septa distant. Stipitipellis a cutis, hyphae cylindrical, 3.7–8.75 µm diam., with straw yellow intracellular pigment, thin-walled, septate (n = 20). Caulocystidia absent. Clamp connections present. Refractive hyphae present.

Habitat:—Solitary, in soil with litter, in the domain of the Amazon Forest.

Distribution:—Known only from the material collected in Belém, Pará.

Comments:— Aside from the African species, E. roseomurinum (Romagn. & Gilles) Noordel. & Co-David (2009: 173) , E. mocambaense does not resemble any named species of Entoloma and differs from this species by the combination of a brownish beige-pink delicate basidiome with a strongly translucent-striate pileus, the presence of clavate cheilocystidia, and cuboidal basidiospores with scarcely elongated angles. It is placed in the /Cervinum subclade, along with other species having a delicate basidiome and cuboidal basidiospores with scarcely elongated angles.

Figures

FIGURE 22. Entoloma mocamboense (FK1899): a. basidiospores; b. basidia; c. cheilocystidia. Scale: 10 µm.

FIGURE 38. Basidiomas: a–b. Entoloma cervinum: a. FK0940; b. FK1770; c–e. E. dragonosporum: c. FK2100; d. FK2019; e. FK2095; f. E. mocamboense (FK1899); g–h. E. tenue: g. FK1039; h. FK1922. Photos: a–f, h: F. Karstedt, g: C. Puccinelli. Scale: 1 cm.