Marasmiellus celebanticus Pérez-De-Greg., Vizzini, Contu & Roqué, 2011

Pérez-De-Gregorio, Miquel-Angel, Vizzini, Alfredo, Contu, Marco, Roqué, Carles & Ercole, Enrico, 2011, Marasmiellus celebanticus (Agaricales, Omphalotaceae), a new species of Marasmiellus sect. Candidi collected in the Mediterranean area, Phytotaxa 25, pp. 49-59 : 51-56

Marasmiellus celebanticus Pérez-De-Greg., Vizzini, Contu & Roqué , spec. nov.

Figs. 1 – 4 MycoBank: MB 561697

Pileus 10–30 mm latus, convexus dein applanatus, saepe ad medium depressus et umbonatus , glaber vel minute fibrillosus, ad medium tomentosus , hygrophanus, pallide brunneus deinde obscurior, aetate fusco-brunneus, margine striato. Lamellae distantes, in juventute saepe leviter furcatae vel anastomosatae, albidae deinde pallide brunneae, adnatae vel adnato-subdecurrentes. Stipes 25–30 × 2–4(–5) mm, centralis, cylindricus sed saepe ad basim incrassatus, insititius , in juventute albus deinde fuscobrunneus vel subniger versus basim, tenuiter fibrillosostriolatus, pruina alba omnino obtecto. Caro parce conspicua, haud gelata, alba , immutabilis. Odor saporque debiles, haud notabiles. Sporae (10–)12–16(–17.5) × (4–)5–6(–6.5) μ m, in medio 13.8 × 5.3 μ m, elongatolarmiformes, tenuitunicatae, haud amyloideae. Basidia 30–36 × 8–11 μ m, 1–4 spora, clavata, sine granulis siderophilis. Cheilocystidia 40–46 × 11–14 μ m rara et dispersa, clavata, haud appendiculata, haud digitata tenuitunicata . Pleurocystidia nulla. Pileipellis haud gelata, ex hyphis jacentibus subparallelis (xerocutis-typi), cylindricis, 6–10 μ m latis, ex pigmento zebranti brunneo incrustatis efformata; pileocystidia 30–60 × 10–20 μ m, variabillima, cylindrica, fusiformes, clavata vel ventricoso-capitata, tenuitunicata , interdum ex cristallis amorphis incrustata. Stipitipellis in cute efformata, hyphae cylindricae, usque ad 6 μ m latae; caulocystidia, 20–35 × 8–10 μ m, abundantia, irregulariter clavata vel ventricoso-capitata, haud vel raro appendiculata vel digitata; stipititrama haud sarcodimitica. Fibulae praesentes. Hyphae basidiocarpi haud amyloideae vel dextrinoideae.

Habitat: gregaria ad culmos vel ad quisquilias Phragmitis australis . Aestivus et autumnalis.

Type :— SPAIN. Girona : Bassa del Burro (Tamariu), Palafrugell, 14 July 2010, C . Roqué & M. A. Pérez-De-Gregorio ( TO HG2281 holotypus) .

Pileus 15–30 mm broad, convex then applanate, often shallowly depressed at the center, sometimes with a low umbo, glabrous to minutely fibrillose, tomentose to very tomentose at centre, light brown, caramel (6C6– 4) then darker, brown, dark brown (7E5–6, 7F5–6) in age ( Fig. 1a,b , 2a ). Margin incurved then deflexed or straight, revolute in old specimens, slightly undulated, translucently striate, hygrophanous ( Fig. 1a,b , 2a ). Lamellae moderately distant (L= 20–35, l= 0–2), sometimes forked to anastomosing in young specimens, adnate to adnate-subdecurrent, white (1A1, 1B1) to pale brown (6 C4–5, D4–5), with a concolorous, finely pubescent edge ( Fig. 1a,b , 2a ). Stipe 25–30 × 2–4(–5) mm, central, at first stuffed then hollow, cylindrical often with a broadened to bulbous base, insitituous; completely white (1A1, 1B1) in young specimens, then turning brownish-grey to dark brown (6F2–3–4) from base upwards, finely fibrillose striate, entirely covered with a persistent, white pruinose covering ( Fig. 1a,b , 2a ). Context very thin, fragile, not gelatinized, white, not changing color ( Fig. 2a ); odor not distinctive and taste mild. Spore print white. Basidiospores (10–)12–16(– 17.5) × (4–)5–6(–6.5) µm, on average 13.8 × 5.3 µm, Q = 2.25–2.80 (2.91), Qm = 2.6, elongate-lacrymoid, thin-walled, non-amyloid, with one or more internal oil drops ( Fig. 2c ). Germinated spores with sinuous, 8–10 µm long germ tubes ( Fig. 2d ). Basidia 30–36 × 8–11 µm, clavate, non-siderophilous, with clamp connections, 1-spored to 4-spored, very variable from specimen to specimen (the average of 100 basidia from six specimens studied is 37% 1-spored, 32% 2-spored, 8% 3-spored and 23% 4-spored, while two of the specimens had more than 90% 1-spored basidia) ( Fig. 2b ). Cheilocystidia rare and scattered, 40–46 × 11–14 µm, clavate, without apical excrescences, thin-walled ( Fig. 3e ). Pleurocystidia absent. Pileipellis a cutis consisting of cylindrical, thin-walled, 6–10 µm wide hyphae, with a very pale brownish zebra-incrusting pigment ( Fig. 4h ); pileocystidia 30–60 × 10–20 µm, morphologically highly variable, cylindrical, fusiform, clavate or ventricose-capitate, thin-walled, occasionally with encrusting crystals ( Fig. 3f ; Fig. 4h ). Stipitipellis a cutis of parallel, thin-walled, up to 6 µm wide hyphae ( Fig. 4i ), with abundant, irregularly clavate or ventricose-capitate caulocystidia, 20–35 x 8–10 µm, very rarely with low apical excrescences ( Fig. 3g ; Fig. 4i ); stipititrama not sarcodimitic. Clamp connections present and abundant.

Chemical reaction:—No part of basidiome amyloid or dextrinoid.

Habitat and distribution:—Gregarious but not caespitose, on dead culms of Phragmites australis living in ponds of water saturated in calcium bicarbonate. Summer and autumn (July to October). Known only from Spain.

Etymology:—From Iugum Celebanticum (lat.), toponym included in the Ora Maritima (Rufus Festus Avienus, 4th century AD) attributed to the Sant Sebastià and Begur capes, around the type locality of this species.

Additional collections examined:— SPAIN. Girona: Palafrugell, Bassa del Burro (Tamariu), 10 August 2010, C. Roqué & M.A. Pérez-De-Gregorio (PG100810-1); ibid, 5 October 2010, C. Roqué (CRP-05102010).

Figures

FIGURE 1. Marasmiellus celebanticus. a, b. Basidiomes in situ. a (PG100810-1), b (holotype). c. Sampling site.

FIGURE 2. Marasmiellus celebanticus. Macroscopical and microscopical characters (from the holotype). a) Basidiomes. b) Basidia. c) Spore. d) Germinated spores.

FIGURE 3. Marasmiellus celebanticus. Microscopical characters (from the holotype). e) Cheilocystidia. f) Pileocystidia. g) Caulocystidia.

FIGURE 4. Marasmiellus celebanticus. Microscopical characters (from the holotype). h) Pileipellis. i) Stipitipellis.