Entoloma dragoluteum 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 : 31-33

Entoloma dragoluteum Karstedt & Capelari , sp. nov.

Figs. 11 , 17a–c , 37d–e

MB 838591

Etymology:— Drago refers to the obvious similarity to the spores of E. dragonosporum ; luteum refers to the color of the basidiome.

Diagnosis:— Entoloma dragoluteum is characterized by the combination of a basidiome with a strongly translucent-striate yellow-brown conical pileus often having a well-developed papilla and a stipe varying from yellow to ochre, pale yellowish lamellae, cuboidal basidiospores with elongated angles, which sometimes resemble a star, cylindrical to clavate cheilocystidia and a pileipellis as a cutis with entangled, prostrate hyphae in transition to a trichoderm.

Type:— BRAZIL. Santa Catarina: Itapoá, Volta Velha Private Natural Heritage Reserve , Sambaqui Trail , 11 December 2012, F. Karstedt et al. FK2131 (Holotype, FLOR) .

Description:— Pileus 5–23 mm diam., 5–15 mm tall, conical with a conical apex or with an elongated papilla, yellow, light brownish yellow, yellow-brown or ochre, with margin often paler, strongly translucent-striate, hygrophanous, surface glabrous, slightly adpressed-fibrillose, margin of the pileus smooth to dentate, papilla generally pronounced, 1–3 mm diam., concolorous with the pileus, translucent. Pileus context thin. Lamellae adnexed, adnexed-sinuate or sinuate, faces smooth, ventricose (<2.5 mm at broadest part), yellowish, beige-pink or pink, close with two tiers of lamellulae, margins entire or irregular, concolorous with faces. Stipe 30–50 × 1–3 mm, cylindrical or attenuated upwards, centrally attached, yellow, slightly paler at the apex, surface slightly adpressed-fibrillose, hollow, with white basal tomentum. Stipe context yellow-brown, translucent. Odor indistinct, taste not observed. Spore print not observed.

Basidiospores cuboidal with elongated angles, sometimes resembling a star with 4–6 projections, 4-angled in profile, excluding the projections 6.2–8.7 × 7.5–8.7 µm [xm = 7.45 (± 0.46) × 7.83 (± 0.51) µm, Q = 1–1.2, Qm = 1.04 (± 0.07), n = 52/5], including the projections (7.5–)8–11.2 × 8.7–12.5 µm [xm = 9.35 (± 0.79) × 10 (± 0.91) µm, Q = 1–1.33, Qm = 1.09 (± 0.1), n = 50/5] and diagonally 10–13.7 × 11–15 µm [xm = 11.77 (± 0.8) × 12.4 (± 0.93) µm, Q = 1– 1.12, Qm = 1.05 (± 0.04), n = 50/5], thin-walled. Basidia clavate or narrowly clavate, 32–42 × 11–13.7 (–16) µm (n = 44/5), hyaline, walls thin or thickened, 4-sterigmate. Cheilocystidia abundant, of the ‘serrulatum-type’, along the entire lamellar margin, cylindro-clavate, clavate or cylindrical-tortuose, 33–100 × 6.2–12.5 µm (n = 53/4), hyaline, thin-walled. Pleurocystidia and pseudocystidia absent. Lamellar trama of parallel, cylindrical or sometimes branched hyphae, 3.7–18(–25) µm diam. (n = 92/5), hyaline, sometimes with incrusted pigment, thin-walled, sub-hymenium branched. Pileitrama composed of radially-arranged hyphae, 5–20 µm diam. (n = 33/3), cylindrical or broadly cylindrical, hyaline, thin-walled. Pileipellis a cutis of slightly entangled, prostrate hyphae, with transition to a trichoderm, hyphae cylindrical, (3.7–)5–12.5 µm diam. (n = 70/5), hyaline or with a little straw yellow intracellular pigment, sometimes with straw yellow incrusted pigment, thin-walled; terminal hyphae not differentiated, cylindrical, broadly cylindrical, cylindro-clavate, with rounded apex, 62–250 × 8.7–19 µm (n = 26/5). Stipitipellis a cutis of prostrate, cylindrical hyphae, 3.7–10 µm diam. (n = 36/2), hyaline, or with a little straw yellow intracellular pigment, walls thin or slightly thickened. Caulocystidia cylindro-clavate or clavate, 35–88 × 6.2–11.2 µm (n = 5/2), hyaline or with a little straw yellow incrusted pigment, walls thin or slightly thickened. Clamp connections present in all tissues. Refractive hyphae present in the trama of the lamellae and the pileus.

Habitat:—Gregarious or scattered, in litter with sand, in restinga forest of the Atlantic Forest biome.

Distribution:— Entoloma dragoluteum is described here from the coast of the state of Santa Catarina.

Additional material examined:— BRAZIL. Santa Catarina: Itapoá, Volta Velha Private Natural Heritage Reserve, Casa de Vidro Trail , 10 December 2012, F. Karstedt et al. FK2104 ( FLOR) ; Sambaqui Trail , 11 December 2012, F. Karstedt et al. FK2115 (Paratype, FLOR); FK2120 (Paratype, FLOR); FK2122 (Paratype, FLOR) .

Comments:— Entoloma dragoluteum resembles E. asterospermum (Romagn. & Gilles) Noordel. & Co-David. (2009:165) , described from material collected in Africa, as both have cuboidal basidiospores with elongated angles resembling stars and basidia with thickened walls. However, the latter has a brown and convex pileus without a papilla, in addition to larger basidiospores, measuring 11.5–14 × 10–12 µm and the hyphae of the pileipellis contain vacuolar pigment (Romagnesi & Gilles 1979). Based on our phylogenetic analysis ( Fig. 3 ) Entoloma dragoluteum is closely related to E. dragorufescens but differs morphologically by the color of the basidioma, as Entoloma dragoluteum is yellow-brown and E. dragorufescens is reddish.

Figures

FIGURE 3. Phylogenetic reconstruction of the species of Entolomataceae with cuboid basidiospores and related species based on the combined genes (nLSU, mtSSU, rpb2 and tef1). Bootstrap values (> 70%) from the maximum likelihood analysis are indicated above the branches. The species studied here are shown in boldface. AU: Australia, AT: Austria, BZ: Belize, BR: Brazil, CN: China, GY: Guyana, IN: India, MY: Malaysia, NZ: New Zealand, PG: Papua New Guinea, PR: Puerto Rico, RE: La Reunion, UK: Russia, SC: Seychelles, US: United States, VN: Vietnam. Dashed vertical line: have similarity in the morphology but no molecular support.

FIGURE 11. Entoloma dragoluteum: a–b. basidiospores: a. FK2115; b. FK2122; c. basidium with a thin wall and with a thickened wall (FK2115); d. cheilocystidia (FK2115); e. pileipellis with pigmented hyphae and with encrusted hyphae (FK2115). Scales: a–d: 10 µm, e: 20 µm.

FIGURE 17. Microphotography of basidiospores in electron microscopy: a–c. E. dragoluteum (FK2120); d–f. Entoloma dragorufescens (FK2102); g–j. E. fraternum (B3074); k–m. E. gatesianum (ACM499). Scale: 5 µm.

FIGURE 37. Basidiomas: a. Entoloma caribaeum (FK1790); b–c. E. dragorufescens: b. FK2102; c. FK2116; d–e. E. dragoluteum (FK2131); f–g. E. lycopersicum: f. TBGAG151; g. TBGAG590. Photos: a–e: F. Karstedt; f–g: R. Maziero. Scale: 1 cm.