Neoboletus antillanus Angelini, Gelardi, Costanzo & Vizzini

Gelardi, Matteo, Angelini, Claudio, Costanzo, Federica, Dovana, Francesco, Ortiz-Santana, Beatriz & Vizzini, Alfredo, 2019, Neoboletusantillanus sp. nov. (Boletaceae), first report of a red-pored bolete from the Dominican Republic and insights on the genus Neoboletus, MycoKeys 49, pp. 73-97 : 78-84

Neoboletus antillanus Angelini, Gelardi, Costanzo & Vizzini sp. nov. Figs 3, 4

Etymology.

the specific epithet antillanus (Latin) refers to the occurrence of the species in the Antilles islands of the Caribbean.

Original diagnosis.

Basidiomes stipitate-pileate with tubular hymenophore characterized by medium-small size, pinkish red to reddish pileus surface, orange-red pores, reddish orange to purple-red punctuations on a yellow stipe surface, golden yellow strigosity at the stipe base, yellow context, tissues bruising dark blue when injured or exposed, ellipsoid-fusiform, smooth basidiospores, ixocutis pileipellis consisting of gelatinized, repent filamentous hyphae and occurrence in neotropical lowland mixed broadleaved forests in putative ECM association with host species ( Coccoloba uvifera ) other than Fagaceae and Pinaceae .

Holotypus.

DOMINICAN REPUBLIC, Municipality of Sousa, Puerto Plata Province, Loc. Cemetery, 19°44'40"N, 70°32'21"W, 100 m a.s.l., 14 Dec 2014, C. Angelini (JBSD127417; isotypus ANGE434 and MG719).

Basidiomes medium-small (Fig. 3). Ontogenetic development gymnocarpic. Pileus (3.0) 3.5-7.5 (8.0) cm broad, at first hemispherical then persistenly convex and finally broadly pulvinate-flattened, sometimes slightly depressed at centre, regularly to hardly unevenly shaped, moderately fleshy, firm at the beginning but progressively softer with age, flabby in old basidiomes; margin steady to faintly wavy-lobed, initially involute then curved downwards, extending beyond the tubes up to 1 mm; surface matt, dry but slightly greasy with moist weather, very finely tomentose, not cracked; cuticle somewhat variable in color, ranging from wine red, dark red or reddish pink to pastel pink (Pomegranate Purple, pl. XII; Spinel Red, pl. XXVI; Pinkish Vinaceous, pl. XXVII; Carmine, Eosine Pink, Geranium Pink, Rose Doree, pl. I; Alizarine Pink, Jasper Pink, Old Rose, pl. XIII), gradually fading with age and becoming pinkish cream to pale ochraceous pink (Flesh Pink, pl. XIII; Pale Ochraceous-Salmon, Pale Ochraceous-Buff, Light Buff, Light Ochraceous-Buff, Warm Buff, pl. XV) with olive-brown to brownish shades (Dresden Brown, pl. XV; Olive Lake, pl. XVI; Light Yellowish Olive, Buffy Olive, pl. XXX) tending to progressively spread from the center towards the peripheral zone; slowly bluing (Methy Green, Sea Green, Prussian Green, pl. XIX; Motmot Blue, Capri Blue, pl. XX) on handling or when injured; subcuticular layer cream-yellowish (Citrine Yellow, pl. XVI). Tubes at first thin then increasingly broader and as long as or slightly longer than the thickness of the pileus context at maturity (up to 1.0 cm long), adnate but soon deeply depressed around the stipe apex, occasionally subdecurrent, bright yellow (Lemon Chrome, pl. IV) to olive-yellow (Yellowish Citrine, pl. XVI), turning blue (Prussian Green, Duck Green, Invisible Green, pl. XIX) when cut and eventually fading to drab yellowish (Aniline Yellow, Pyrite Yellow, pl. IV). Pores initially forming a concave then flat surface, at first small then gradually wider (up to 1 mm in diam.), simple, roundish to barely angular at maturity, at first bright orange-red to orange (Scarlet Red, Scarlet, pl. I) although concolorous with the tubes (Lemon Chrome, pl. IV) towards the margin, soon becoming yellowish orange (Flame Scarlet, Orange Chrome, pl. II) and finally yellowish olive (Yellowish Citrine, pl. XVI) with very pale orange hues (Orange, pl. III), quickly and intensely turning blue (Prussian Green, Duck Green, Invisible Green, pl. XIX) on bruising or when injured. Stipe (3.5) 4.0-9.0 (9.5) × (1.0) 1.5-2.0 (2.5) cm, longer than or as long as the pileus diameter at maturity, central to slightly off-center, solid, firm, dry, straight or curved, at first ventricose-fusiform, later cylindrical but either sligthly swollen towards the base to decidedly clavate or tapering downwards, not to barely rooting, evelate; surface at the apex or in the upper third usually smooth to occasionally very faintly reticulate due to the sub-decurrence of the hymenophore in some specimens and bright yellow (Lemon Chrome, pl. IV) to lemon yellow (Strontian Yellow, pl. XVI), elsewhere showing a fine, purple-red, dark red to orange-red (Indian Lake, pl. XXVI; Amaranth Purple, pl. XII; Carmine, Scarlet Red, pl. I) punctuation (Fig. 2d) partly hiding the bright yellow (Lemon Chrome, pl. IV) ground color; the base is typically wrapped by a conspicuous golden yellow to brownish yellow strigosity (Fig. 2d) (Raw Sienna, pl. III; Yellow Ocher, pl. XV); bruising greenish blue (Light Blue Green, Blue Green, Forest Green, pl. XVII) throughout when pressed; basal mycelium golden yellow (Raw Sienna, pl. III; Yellow Ocher, pl. XV). Context firm when young, later soft textured and eventually flabby in the pileus (up to 1.0 cm thick in the central zone), a little more fibrous in the stipe, lemon yellow (Strontian Yellow, pl. XVI) throughout, usually with purple-brown (Indian Lake, pl. XXVI; Amaranth Purple, pl. XII) spots in the stipe, especially at the extreme base; turning blue (Methy Green, Sea Green, Prussian Green, pl. XIX; Motmot Blue, Capri Blue, pl. XX) more or less evenly when exposed to air and finally fading to drab yellowish (Aniline Yellow, Pyrite Yellow, pl. IV); subhymenophoral layer lemon yellow (Strontian Yellow, pl. XVI). Odour and taste not distinctive. Spore-print not obtained but likely olive-brown.

Basidiospores [102/5/3] (8.8) 11.1 ± 0.78 (12.7) × (4.1) 4.9 ± 0.26 (6) μm, Q= (1.85) 1.96-2.54 (2.57), Qm= 2.24 ± 0.12, V= 143 ± 23 μm ³, inequilateral, ellipsoid-fusiform to ellipsoid in side view, ellipsoid in face view, smooth, apex rounded, with a short apiculus and with a shallow suprahilar depression, moderately thick-walled (0.5-0.9 μm), honey yellow colored in water and 5% KOH, having one or two large oil droplets when mature, rarely pluri-guttulate, inamyloid to very faintly dextrinoid, acyanophilic and with an ortochromatic to very faint metachromatic reaction (Fig. 4a). Basidia 24-48 × 10-13 μm (n= 26), cylindrical-clavate to clavate, moderately thick-walled (0.5-0.8 μm), predominantly 4-spored but also 1- or 2-spored, usually bearing relatively short sterigmata (2-6 μm), hyaline to pale yellowish and containing straw-yellow oil guttules in water and 5% KOH, bright yellow (inamyloid) in Melzer’s, without basal clamps (Fig. 4b); basidioles subcylindrical to faintly clavate, similar in size to basidia. Cheilocystidia (19) 21-56 × 4-9 (11) μm (n= 23), very common, moderately slender, projecting straight to sometimes flexuous, irregularly cylindrical or cylindrical-fusiform, fusiform to narrowly lageniform, showing a narrow and long neck, with rounded to subacute tip, smooth, moderately thin- to slightly thick-walled (0.3-0.9 μm), hyaline to pale yellowish in water and 5% KOH, bright yellow (inamyloid) in Melzer’s, without epiparietal encrustations (Fig. 4d). Pleurocystidia (41) 44-55 × 5-11 μm (n= 14), uncommon, shape, color and chemical reactions similar to but usually longer than cheilocystidia (Fig. 4d). Pseudocystidia not recorded. Pileipellis (Fig. 4e) an ixocutis consisting of strongly interwoven, elongated, filamentous and sinuous, frequently branched, repent to occasionally erect hyphae heavily embedded in gelatinous matter; terminal elements 20-72 × 3-9 μm, long and slender, cylindrical, apex pointed, moderately thick-walled (up to 1 μm), pale yellow to golden yellow in water and 5% KOH, inamyloid in Melzer’s, smooth to sometimes ornamented by a subtle zebra-like epiparietal encrustation; subterminal elements similar in shape, size and color to terminal elements. Stipitipellis a texture of slender, parallel to subparallel and longitudinally running, smooth-walled, adpressed hyphae, 3-11 μm wide, hyaline to yellowish in water and 5% KOH; the stipe apex covered by a well-developed caulohymenial layer consisting of sterile clavate caulobasidioles, abundant, predominantly 4- or 2-spored, fertile caulobasidia and projecting, irregularly cylindrical or cylindrical-fusiform, ventricose-fusiform to fusiform, sublageniform to rarely short mucronate caulocystidia (Fig. 4c) similar in shape and color to but slightly broader than hymenial cystidia, (23) 25-45 (54) × 5-13 (15) μm (n= 16), having a wall up to 0.8 μm thick. Lateral stipe stratum under the caulohymenium present and well differentiated from the stipe trama, of the "boletoid type", at the stipe apex a (20) 30-40 (50) μm thick layer consisting of divergent, inclined and running towards the external surface, loosely intermingled and branched hyphae remaining separate and embedded in a gelatinous substance. Stipe-trama composed of densely arranged, subparallel to moderately interwoven, frequently septate, cylindrical to filamentous, smooth, inamyloid hyphae, 4-13 μm broad. Basal tomentum hairs 40-150 μm thick, consisting of tightly adpressed, parallel to subparallel, septate, filamentous, occasionally branched, relatively thick-walled (up to 0.8 μm) hyphae, 2-5.5 μm wide, terminal elements with blunt apex, pale yellow to honey yellow in water and 5 % KOH. Hymenophoral trama bilateral divergent of the “Boletus-type”, with slightly to strongly divergent, recurved-arcuate and loosely arranged, often branched, restricted at septa, gelatinous hyphae (lateral strata hyphae in transversal section not touching each other, (2) 4-8 (10) μm apart, 3-13 μm broad), hyaline to very pale yellowish in water and 5% KOH, inamyloid in Melzer’s; lateral strata (20) 30-50 (60) μm thick, mediostratum (20) 30-60 (70) µm thick, axially arranged, consisting of a tightly adpressed, non-gelatinous bundle of hyphae, 3-10 µm broad; in Congo Red the mediostratum is darker than the lateral strata. Thromboplerous hyphae (= oleiferous hyphae sensu Clémençon 2004) very common and particularly frequent in the hymenophore, golden yellow in 5% KOH. Clamp-connections absent everywhere. Hyphal system monomitic.

Ecology.

solitary to gregarious, growing on limestone among litter in a seasonally dry and moist anthropised lowland mixed stand under a large array of neotropical broadleaved trees, including Coccoloba uvifera , which represents its probable ECM host tree. See Parra et al. (2018) for further details on vegetation.

Edibility.

Unknown.

Examined material.

DOMINICAN REPUBLIC, Municipality of Sousa, in Puerto Plata Province, Loc. Cemetery, 19°44'40"N, 70°32'21"W, 100 m a.s.l., a single middle-aged specimen, 03 Dec 2014, C. Angelini (JBSD127416, ANGE425 and MG718); same loc., two young to mature specimens, 14 Dec 2014, C. Angelini (JBSD127417, Holotype, ANGE434 and MG719, Duplo); same loc., several dozens of specimens, most of which heavily parasitized by Hypomyces sp., 01 Dec 2017, C. Angelini (JBSD127418, ANGE958 and MG720).

Known distribution.

Presently only known from the type locality in the Dominican Republic (Greater Antilles, Caribbean).