Macrolepiota capelariae A.D. Souza, C.C. Nascimento & Menolli, 2022

Souza, Adriana D., Do Nascimento, Cristiano C., Freitas, Daline S. & Jr, Nelson Menolli, 2022, Macrolepiota capelariae (Agaricaceae, Basidiomycota): a new species from the Brazilian Atlantic Rainforest with extended records to Argentina and Mexico, Phytotaxa 576 (3), pp. 265-278 : 270-273

Macrolepiota capelariae A.D. Souza, C.C. Nascimento & Menolli sp. nov. ( Figs. 2–4 )

MycoBank: MB 844529

Diagnosis:—Similar to Macrolepiota colombiana but differing in brownish orange or clay brown, light brown to pale greyish brown pileus surface, mostly breaking up into radially arranged interwoven strips, and then exposing a whitish background, the less complex annulus, the unchanging context, the non-septate cheilocystidia, and absence of clamp connections.

Etymology:—‘ capelariae ’, in honor of Dr. Marina Capelari, a dedicated Brazilian mycologist for her contribution to the taxonomic study of mushrooms from Brazil for more than 30 years during her career.

Holotype:— BRAZIL. S„o Paulo: S„o Paulo , Parque Estadual das Fontes do Ipiranga, 14 January 2022, D.A. Zabin & M.C.S. Pires DAZ060 (SP513052), GenBank [nrITS]: ON753531 , [nLSU]: ON794497 .

Paratypes:— BRAZIL. S„o Paulo: S„o Paulo , Parque Estadual das Fontes do Ipiranga, 24 July 2010, M. Capelari, P.O. Ventura & N. Menolli Jr. MC4584 (SP513053), GenBank [nrITS]: ON753533 , [nLSU]: OP302841 ; ibid. 06 December 2010, M. Capelari MC4588 (SP513054), GenBank [nrITS]: ON753532 , [nLSU]: OP302842 ; ibid. 20 March 2015, D.S. Freitas DSF02 (SP513055), GenBank [nrITS]: ON753529 ; ibid. 800 m a.s.l, 26 February 2016, A.D. Souza & L.S. Ramos ADF04 (SP513056), GenBank [nrITS]: ON753530 ; ibid. 03 March 2016, A.A. Alcântara AL228 (SP513057), GenBank [nrITS]: ON753534 .

Description:— Basidiomata medium to large-sized. Pileus 78–120 mm diam., fleshy, ovoid to hemispherical when young, expanding to broadly campanulate, convex, rounded-umbonate, obtuse umbonate to plano-umbonate, sometimes applanate with a slightly reflexed margin with age; surface dry, at first brownish yellow (N 20 Y 70-90 M 30) to brownish orange (N 20 Y 70-90 M 30), then light brown (Y 30-40 M 30 C 20, Y 40 M 30-40 C 30) to pale greyish brown (N 40 Y 30-50 M 20), brownish orange (Y 60 M 30-40 C 10-20) or clay brown (Y 40 M 50 C 20), breaking up into radially arranged interwoven strips, but sometimes into small to large patch-like squamules (easily detachable from the pileus), and then exposing a whitish background; disc smooth, dark brown (N 80 A 90 M 50 –N 90 A 20 M 60) to reddish brown (N 50 Y 80 M 50 –N 60 Y 80 M 70). Lamellae free, remote from the stipe, crowded, ventricose, white when young, white to beige (Y 20 M 10 C 10) when mature, sometimes with brownish spots; lamellulae attenuate, in 1–2 ranks, unevenly distributed; edge entire, smooth, concolorous. Stipe 150–320 × 5–18 mm, central, subcylindrical, gradually attenuating upwards, bulbous at base; bulb subglobose, 20–25 mm wide, completely covered by a tomentose-velvety whitish mycelial layer, often with long white rhizomorphs; surface medium brown (N 50 Y 60 M 30 –N 60 Y 40-50 M 40), paler upwards, finely fibrillose, sometimes breaking open into pale brown (Y 60 M 50 C 50) zigzagging bands over the middle zone on an off-white background. Annulus superior, membranous, beige (N 40 A 10 M 10) at the upper side, pale brown at underside, with a broken brownish margin, movable when mature. Context in the pileus white and moderately thick, in stipe white and hollow with a central white cottony strand, unchanging in both. Odor fungoid. Taste mild, sweet. Spore print white.

Basidiospores [255/16/16] (8.8–)12.5–15.0(–17.5) × (5.8–)7.5–11.2(–11.8) µm (L m = 13 µm; W m = 8.5 µm; Q = 1.3–2.0; Q m = 1.54), ellipsoid to elongate, with germ pore covered by hyaline cap, smooth, hyaline, thick-walled, dextrinoid, congophilous, metachromatic in Cresyl blue; apiculus about 1 µm long. Basidia 22–42 × 11.2–15.0(– 16.2) µm, clavate, hyaline, thin-walled, 1–4-spored. Lamella edge sterile, with crowded cheilocystidia. Cheilocystidia 21–50 × 9.0–15.0(–16.5) µm, narrowly clavate, sometimes clavate, often catenulate, hyaline, colorless, thin-walled. Pleurocystidia absent. Pileus covering a trichoderm composed of 4–6 layers of elements, often branching; lower layer elements subglobose, broadly clavate to oblong, seldom cylindrical, 18.0–32 × 11.0–25 µm, slightly thick-walled to thick-walled, with pale yellowish brown intracellular pigments, walls sometimes encrusted; upper layer elements mostly clavate to narrowly clavate, 11.5–32 × 3.0–11 µm, slightly thick-walled to thick-walled, with hyaline to pale yellowish brown parietal pigment. Stipe covering a hymeniderm of cylindrical elements, 6.2–14.7 µm wide, thinwalled, with intracellular pale brown content. Clamp connections absent.

Habitat and distribution:—Saprotrophic and terrestrial, growing in a remnant of Atlantic Rainforest, under shade trees, solitary or in small groups, known from the state of S„o Paulo, Southeastern Brazil (type locality). Based on records from GBIF, Mushroom Observer , and GenBank ( MN847716 and MH290361 ), the species distribution can be extended to Argentina and Mexico, and putatively to five other Brazilian states: Acre , Paraná , Rio de Janeiro , Rio Grande do Sul, and Santa Catarina.

Additional specimens examined:— Brazil, SP, S„o Paulo , Parque Estadual das Fontes do Ipiranga ( PEFI), 800 m a.s.l., 14 October 1998, L. Gusmão s.n. (SP513059) ; ibid. 15 October 1998, M. Capelari s.n. (SP513060) ; ibid. 10 October 2001, U.C. Peixoto s.n. (SP381602) ; ibid. 26 December 2001, U.C. Peixoto s.n. (SP381601) ; ibid. 05 September 2002, U.C. Peixoto s.n. (SP381603) ; ibid. 11 December 2003, M.D.F. Trude LJG 022/03 (SP381600) ; ibid. 30 January 2008, T. V. S. Campacci s.n. (SP513061) ; ibid. 04 April 2012, M. Capelari MC4692 (SP513062) ; ibid. 26 February 2016, A.D. Souza ADF03 (SP513058) .

Figures

FIGURE 2. Macrolepiota capelariae (SP513052, holotype). A. Young basidiomata. B. Mature basidioma. C. Detail of the lamellae. D. Detail of the annulus. E. Detail of the stipe base. Scale bars = 20 mm. Photos by D.A. Zabin.

FIGURE 3. Putative records of Macrolepiota capelariae outside the type locality. Data from GBIF/iNaturalist and Mushroom Observer. A–K. Brazil (A, J, K: Rio de Janeiro, RJ; B: Rio Branco, AC; C: Lajeado, RS; D: Jaraguá do Sul, SC; E: Florianópolis, SC; F: Palmeira, PR; G: S„o Sebasti„o da Grama, SP; H: Vitorino, PR; I: Senador Guiomard, AC). L. Mexico (Tepoztlán, Morelos). Brazilian states abbreviations:AC =Acre, PR = Paraná, RJ = Rio de Janeiro, RS = Rio Grande do Sul, SC = Santa Catarina, SP = S„o Paulo.Photo credits: A. ©Rogerio Dias, B. ©Gabriel Fernando, C. ©Edith Mello, D. ©fernandotorres1978, E. ©Mariana Lopes, F. ©andersonwarkentin, G. ©Café Gato-Mourisco, H. ©Alan Lucas Hentz Policarpo, I. ©Mayk Oliveira, J. ©rogerriodias, K. ©Alessandro Valente Vieira, L. ©Alejandro Tux.

FIGURE 4. Macrolepiota capelariae (SP513052, holotype). A. Mature basidioma, a. Detail of the pileus surface. B. Apical thick-walled elements of the pileus covering. C. Pileus covering. D. Basidia. E. Cheilocystidia. F. Basidiospores. Scale bars: A/a = 10 mm; B–F = 10 µm. Drawings:A/a by K. Sousa, B–F original by C.C. Nascimento and inked by K. Sousa.