Tylopilus dunensis A.C. Magnago & M.A. Neves, 2017

Magnago, Altielys Casale, Reck, Mateus Arduvino, Dentinger, Bryn T. M., Moncalvo, Jean-Marc, Neves, Maria Alice & Silveira, Rosa Mara Borges Da, 2017, Two new Tylopilus species (Boletaceae) from Northeastern Atlantic Forest, Brazil, Phytotaxa 316 (3), pp. 250-260 : 255

Tylopilus dunensis A.C. Magnago & M.A. Neves , sp. nov. Fig. 3 .

Mycobank: MB 819523 Type: — BRAZIL, Rio Grande do Norte, Natal, Parque Estadual Dunas do Natal, Trilha da Geografia, growing on white sand soil on dunes,

24 April 2008, Neves MA 218 (holotype: HUEFS138281 !; isotype: FLOR51718 !) GenBank accession: ITS = MF113419, 28S =

MF113428. Etymology: — from the Latin dunensis = referring to the habitat (white sand dune area) where the new species was collected.

Pileus 25−115 mm broad, at first convex, with age becoming plano-convex to plano-depressed, yellow orange (OAC 789), to bright orange (OAC 644) with some red tones (OAC 670), finely velutinous under lens, dry, margin slightly inrolled and entire; context 5−14 mm centrally, whitish to yellowish (OAC 815), unchanging when exposed. Tubes 4−13 mm long, whitish to cream (OAC 816), slightly decurrent; pores 1−2 mm broad, whitish, staining light orange brown upon pressure. Stipe 30−65 × 8−28 mm, central to eccentrical, subequal, whitish to cream yellow (OAC 814); smooth, context cream (OAC 815), unchanging; extreme base with white mycelium. Macrochemical reactions: NH 4 OH unchanging on pileus and stipe surfaces.. Spore print pinkish.

Basidiospores 6−9 × 3−4 μm (Qm=1.91), ellipsoid to elongate in frontal view, the inner side applanate to bean shaped (phaseoliform) in side-view, in mass light yellow, inamyloid to weakly dextrinoid, smooth, thin walled; hilar appendage 0.5−1 μm long. Basidia 27−40 × 6−10 μm, clavate, thin walled, hyaline, many with granular contents; 4-sterigmate, 4−6 μm long. Cystidia abundant both on pores (cheilocystidia) and tubes (pleurocystidia), similar in size and shape, 32−82 x 6−13 μm, fusoid, ventricose, some clavate, hyaline, but also many with golden contents, dextrinoid. Hymenophoral trama boletoid, mediostratum of subparallel to interwoven hyphae, 3−5 μm wide, lateral stratum hyphae 5−8 μm wide, divergent, inamyloid. Pileipellis a trichodermium, interwoven in a gelatinized matrix, hyphae 2−5 μm wide, light brown with golden brown contents, dextrinoid, hyphae regularly septate. Pileus trama interwoven to subparallel, partly gelatinized, light yellow, with dextrinoid contents. Stipitipellis in two layers, external layer hymeniform, with terminal cells 5−13 μm wide, hyaline, some with golden contents; presence of caulobasidia and caulocystidia in variables shapes, including clavate, cylindrical, fusoid, ventricose, and capitate; lower layer with narrow hyphae with golden brown contents as observed in H 2 O, 2−4 μm wide, interwoven vertically arranged in a gelatinized matrix. Stipe trama parallel to subparallel, hyphae 4−15 μm broad, hyaline, inamyloid, smooth and thin walled. Clamp connection absent.

Habit and habitat: — Solitary to scattered, sometimes caespitose, growing on white sand dunes in restinga vegetation in the far north of costal Atlantic Forest.

Specimens examined (paratypes): — BRAZIL, Rio Grande do Norte, Natal, Parque Estadual Dunas do Natal , 5°51’S, 35°11’W, 24 April 2008, 216 ( HUEFS138279 !, FLOR51716 !) GenBank accession: ITS = MF113418 ; 29 April 2008, Neves MA 255 ( HUEFS138318 !), 256 ( HUEFS138319 !), 258 ( HUEFS138321 !), 24 May 2008, Neves MA 281 ( HUEFS138368 !) GenBank accession: ITS = MF113420 .

Additional specimens examined: — AUSTRALIA, Queensland, Tylopilus balloui Fraser Island, road from Central Station to Eurong. 25°29’6’’S, 153°5’18’’E, 11 February 2009, Halling RE 9053 (NY!). BELIZE, Cayo District, Tylopilus balloui Mountain Pine Ridge : Douglas Da Silva, British Military Swamp. 16°58’9’’N, 88°59’38’’E, 6 October 2003, Halling RE 8526 (NY!). COSTA RICA, Cartago, Tylopilus oradivensis, Guarco, Palo Verde. +/_ 4.5 km E of km 31 of Interamerican Highway. 9°46’34’’N, 83°56’42’’W, 1 June 2001, Halling RE 8087 (NY!).

Comments: — Tylopilus dunensis is morphologically similar to the North American Tylopilus balloui Peck (1912: 157) . Both have a yellow-orange to orange-red pileus, white to cream hymenophore, cream to pale yellow stipe and do not change color when in contact with ammonium; basidiospores are shorter than 10.5 μm long and the pileipellis is trichodermium. Tylopillus balloui , however, does not have a gelatinized pileipellis, the trama has gloeopleurous hyphae, the pseudocystidia are fusoid ventricose to broadly-ventricose to ventricose-mammilate and abundant, the cheilocystidia are spheropedunculate to broadly spheropedunculate, and the caulocystidia are clavate to fusoid ventricose with staining contents restricted to the cytoplasm and interrupted by hyaline vacuoles, as observed by Wolfe (1981) in the type studies of Tylopilus described by Charles H. Peck.

Osmundson & Halling (2010) described Tylopilus oradivensis Osmundson & Halling (2010: 476) from Costa Rica as part of the balloui complex based on morphological and molecular data. This species differs from T. dunensis by having a reddish orange to red pileus and stipe and larger (8.2−12 × 3−4 μm) subfusiform to fusiform basidiospores.

Figures

FIGURE 3. Tylopilus dunensis. A—Photographs of fresh basidiomes in the field. B-C—Basidiospores; D—Basidia; E—Cystidia; F— Pileipellis; G—Stipitipellis. Bar 10 μm.