Entoloma brunneoapplanatum K. N. A. Raj & Manim., 2016

Anil Raj, K. N. & Manimohan, Patinjareveettil, 2016, Three new species of Entoloma subgenus Nolanea from India based on morphology and molecular phylogeny, Phytotaxa 286 (4), pp. 232-244 : 237-238

Entoloma brunneoapplanatum K. N. A. Raj & Manim. , sp. nov. Figs. 3A–F

MycoBank MB 818068

Etymology:—The specific epithet refers to the brown, applanate pileus of this species.

Diagnosis:—This species is characterized by small, dark brown to brown, mycenoid basidiocarps; a papillate pileus; a fertile lamella-edge devoid of cheilocystidia; 5–6(–7)-angled basidiospores 8–11 × 6.5–8μm; spiral encrustations on hyphae of pileitrama, pileipellis, and stipitipellis; and a distinctive ITS sequence (KX774269).

Holotype:— INDIA. Kerala State: Thrissur District, Chalakudy, Athirapilly Forest Range , Kumbidamudi hill: 14 November 2009, K. N. Anil Raj AR105 ( CAL 1313 ).

Description:— Basidiocarps small, mycenoid. Pileus 4–26 mm diam., plano-convex when very young becoming applanate with a very small central papilla, often surrounded by a shallow depression; surface dark brown (6F4, 6F5/OAC733) at the center and on the striations, brown (6 E4, 6 E5/OAC702) elsewhere, weakly hygrophanous and becoming slightly paler, finely pellucid-striate towards the margin, smooth, glabrous with a sheen; margin slightly incurved and entire when young, becoming straight or rather reflexed and slightly wavy with age. Lamellae emarginate, subventricose to ventricose, subdistant to subclose, pale orange (6A3/OAC668), up to 3.5 mm wide, with lamellulae in 2–3 tiers; edge initially entire, becoming somewhat wavy, concolorous with the sides. Stipe 7–51 × 1–3.5 mm, central, terete, equal, cartilaginous, hollow; surface brown (5F4, 5F5/OAC735), glabrous to the naked eye, finely pruinose at the apex under a lens; base with white mycelial tomentum. Odor and taste not distinctive.

Basidiospores 8–11 × 6.5–8 (9.11±0.99 × 7.21±0.43) μm, Q = 1.1–1.5, Qm = 1.3, mostly 5- or 6-angled or rarely 7-angled in profile, heterodiametric, with at least one concave facet, hyaline or pale yellow, thick-walled. Basidia 17–30 × 8–12 μm, clavate, pale yellow, thin-walled, 4-spored; sterigmata up to 5 μm long. Lamella-edge fertile. Cheilocystidia and pleurocystidia absent. Lamellar trama subregular; hyphae 3–11 μm wide, pale yellow, thin-walled. Subhymenium inconspicuous. Pileitrama subregular; hyphae 6–22 μm wide, with a yellowish brown intraparietal pigment and fine dark brown encrustations, thin- to slightly thick-walled. Pileipellis a cutis; hyphae 4–13 μm wide, with yellowish brown plasmatic contents and dark brown spiral encrustations, thin- to slightly thick-walled. Stipitipellis a cutis; hyphae 4–13 μm wide, with a pale brownish yellow intraparietal pigment and fine, brown encrustations, thinto slightly thick-walled. Caulocystidia absent. Clamp-connections not observed on any hyphae.

Habitat: — in small groups, on soil under broadleaf trees, among humus and decaying leaf litter.

Geographical distribution range:—known only from the type locality in Kerala State, India.

Additional specimens examined:— INDIA. Kerala State: Wayanad District, Kalpetta, Puthurvayal, Community Agro-biodiversity Centre campus, 27 September 2016, K. N. Anil Raj, AR1011.

Comments:—The mycenoid basidiocarps, the glabrous, translucent-striate pileus with a small, central papilla, the cutis-type pileipellis, the heterodiametric basidiospores with a Q value>1.2, the absence of cheilocystidia and the presence of intracellular plasmatic pigment and the encrustations in the pileipellis hyphae lead the present species to the section Papillata of subgenus Nolanea .

Entoloma brunneoapplanatum shows some similarity to Entoloma brunneoquadratum Manim. & Noordel. in Manimohan et al. (2006: 57), a species previously reported from Kerala ( Manimohan et al. 2006), because they both have a weakly hygrophanous, translucent-striate, glabrous pileus with somewhat similar color, an entire, concolorous lamella-edge, a glabrous stipe, somewhat similar-sized basidiospores,lamellae devoid of both cheilo- and pleurocystidia, a cutis-type pileipellis and stipitipellis, and clampless hyphae. However, E. brunneoquadratum has larger basidiocarps, a depressed pileus, free lamellae with a brown color, cuboid-quadrate basidiospores, basidia with a variable number of sterigmata and non-encrusted hyphae. Entoloma acuminatum Horak (1980: 183) , known from Sri Lanka ( Horak 1980; Pegler 1986), also shows some similarity with E. brunneoapplanatum in having a similar-colored, glabrous, translucent-striate pileus, basidiospores of similar size and shape, lamellae devoid of both cheilo- and pleurocystidia and a cutis-type pileipellis with encrusting hyphae. However, E. acuminatum has a conico-campanulate, often acutely umbonate pileus, a stipe with a strigose base, clamped hyphae, and a pseudoparenchymatous subhymenium.

In a BLASTn search of the GenBank nucleotide database using the ITS sequence (668 bp), the closest hit was a collection labelled as Entoloma clandestinum f. cystidiophorum (JX454941) with 91% sequence identity, followed by E. clandestinum (JX454940) and E. malenconii (JX454951) with 91 and 90% sequence identities respectively. Entoloma clandestinum ( Fries 1818: 166) Noordeloos (1980: 456) , a European species ( Noordeloos 1992) that belongs to the section Papillata , shows some similarities in having a glabrous pileus with a very small papilla, similar-sized basidiospores (8–10(11) × 5.5–7.5) with almost similar number of facets (6–7), lamellae devoid of cystidia, and encrustations on the hyphae of both pileitrama and pileipellis. However, E. clandestinum has a conical or hemispherical pileus and clamped hyphae. Entoloma malenconii Vila & Llimona, (2002: 97) , a species of section Mammosa from Spain, is similar to E. brunneoapplanatum in having a somewhat similar-colored, applanate pileus with an umbo at mature stages, somewhat similar-sized basidiospores (8.5–9.6(11) × 6.9–8), and a cutis-type pileipellis with brown encrustations ( Vila et al. 2013). However, E. malenconii differs in having adnate lamellae, many cheilocystidia, and clamp-connections.

Figures

FIGURE 3. A–F: Entoloma brunneoapplanatum (CAL 1313, holotype). A–B. Basidiomata.C. Basidiospores; D. Basidium; E. Pileipellis; F. Pileipellis hypha showing spiral encrustations. Scale bars: A–B = 10 mm; C–F = 10 μm. Photos by K. N. Anil Raj.