Calocybella dominicana Angelini & Vizzini, 2017

Vizzini, Alfredo, Angelini, Claudio & Ercole, Enrico, 2017, Is the species diversity in the lyophylloid genera Calocybella and Gerhardtia (Agaricales, Basidiomycota) underestimated? Two new species from the Dominican Republic, Phytotaxa 291 (4), pp. 241-252 : 244-246

Calocybella dominicana Angelini & Vizzini , sp. nov. ( Figs. 3–5 )

Mycobank MB819494

Diagnosis: — Distinguished by an ochraceous orange, convex to plane, 10–25 mm broad pileus with a brown broad obtuse umbo and covered by a white pruina; adnate-emarginate, whitish lamellae; a white-pruinose stipe with a reddening surface on handling; strong mealy odour and taste; broadly ellipsoid to ellipsoid, inamyloid, cyanophilous, warty basidiospores (4.8–) 4.9–6.0 (–6.2) × (3.8–) 3.9–4.8(–5.5) μm (on average 5.36 × 4.09 μm); a cutis-type, non-gelatinised pileipellis; clamped hyphae, and unique nrLSU and nrITS sequences.

Type:— THE DOMINICAN REPUBLIC. Puerto Plata, Sosúa, Loc. Cemetery, on man-made litter in a deciduous forest, 03 December 2013, C. Angelini , JBSD 126507 , holotype ( JBSD!) ; AH 46062 , isotype ( AH!) .

Etymology:—The epithet refers to the country, the Dominican Republic, where this species was found.

Description:— Basidiomes small, collybioid. Pileus 10–25 mm broad, at first conico-campanulate to hemisphericalcampanulate, then plano-convex, with a broad obtuse umbo; margin non-striate, thin, regular to wavy, sometimes sublobed; surface dry, smooth, matt, slightly hygrophanous, with a somewhat silky appearance owing to a thin coating of white, micaceous pruina all over, which disappears with age, but persisting mainly around the umbo and at the pileus margin; ochraceous brown (Orange-Cinnamon, Cinnamon, Clay Color, Sayal Brown, Plate XXIX), ochraceous orange (Orange, Cadmium Yellow, Plate III; Salmon-Buff, Flesh-Ocher, Apricot-Buff, Plate XIV), darker in the centre, brown (Garnet Brown, Morocco Red, Plate I; Mahogany Red, Plate II), paler (Cartridge Buff, Cream-Buff, Plate XXX) over the margin. Lamellae white, close, adnate-emarginate, 2–3 mm broad; lamellulae l = (0) 1–3 (4); edge slightly eroded and concolorous. Stipe 25–45 × 3–5 mm, cylindrical, equal, straight to sinuous, sometimes curved towards the base, white to pale cream (Cream-Buff, Plate XXX), firm, white-pruinose overall, fibrillose-striate; base subtended by abundant and thin whitish rhizoids; surface more or less rapidly changing to red on bruising. Context thin at pileus centre, whitish, slightly reddening in the stipe, fibrous, elastic. Odour and taste strongly mealy. Spore print not obtained.

Basidiospores (4.8–) 4.9–6.0 (–6.2) × (3.8–) 3.9–4.8(–5.5) μm [40/1/1], on average 5.36 × 4.09 μm, Q = (1.09–) 1.17–1.5 (–1.58), Qm = 1.31, largely ellipsoid to ellipsoid, hyaline, thin-walled, content granular or mono- to multiguttulate, inamyloid, cyanophilous, covered with large, obtuse, and irregular verrucae. Basidia 25–28 × 6.0–7.0 μm, clavate, hyaline, siderophilous (with internal siderophilous/cyanophilous granules), 4-spored; sterigmata up to 3.5 μm long. Hymenial cystidia absent. Hymenophoral trama regular, consisting of parallel to slightly divergent, 4–5 μm wide hyphae. Pileipellis a non-gelatinised cutis (xerocutis) composed of parallel hyphae up to 7.5 μm wide, with some repent hyphae ending with a clavate, up to 50 × 5.0 μm element; with cytoplasmatic yellowish-ochre pigmentation. Stipitipellis similar to the pileipellis, hyphae up to 6.0 μm wide; irregular, up to 25–35 μm long and sometimes repent caulocystidioid hyphae are present along the stipe surface. Stipititrama regular, consisting of parallel, up to 10 μm wide hyphae. Clamp-connections present, common on narrow hyphae of the pilei- and stipitipellis.

Habit, habitat and distribution:—Basidiomes collybioid, gregarious in small groups, on deciduous forest litter. So far, this species has been found in the winter period (December) in the coastal area around Sosúa-Puerto Plata, in a forest consisting mainly of the following tree species Inga vera Willd , Hura crepitans L., Catalpa longissima (Jacq.) Dum.Cours. , (Roxb.) Benth., Piper amalago L., Dendropanax arboreus (L.) Decne. & Planch., Andira inermis (W. Wright) DC. , Cecropia schreberiana Miq. , Bursera simaruba (L.) Sarg. For a detailed botanical characteristics of the collection areas, see Angelini & Losi (2013, 2014).

Notes:— Calocybella pudica (Bon & Contu in Contu & Bon 2000: 35) Vizzini, Consiglio & Setti (in Vizzini et al. 2015: 5), type species of the genus Calocybella and so far known from Italy, France and Spain, shares with C. dominicana the reddening of the stipe surface on bruising, but differs by the entire orange to brownish orange pileus without a darker umbo, yellow to orange lamellae, yellow rhizoids at the stipe base and narrower basidiospores [× (2.8–) 3.0–3.7 (–4.3) μm, Q = (1.3–) 1.46–1.80 (–2.1), Qm = 1.63]; in addition, in most collections, C. pudica typically develops ornamented basidiospores mixed with apparently smooth ones ( Contu & Bon 2000; Contu & Ortega 2001; Picillo & Contu 2009; Vizzini et al. 2015). The three new Calocybella species recently described from India ( Latha et al. 2016) are morphologically quite different from our new species: C. lohitha K.P.D. Latha & Manim. (in Latha e t al. 2016: 134) shows a reddish pileus with a minutely granular surface, dull red lamellae, reddish grey or brownish grey stipe not discoloring on bruising, indistinct odour and taste, and acyanophilous oblong-ellipsoid narrower basidiospores (× 2–3 μm, Q = 1.83–3.0, Qm = 2.31); C. babruka K.P.D. Latha & Manim. (in Latha et al. 2016: 137) is characterised by a slender tricholomatoid habit, a brown pileus with granulose surface and a lobate margin, greyish orange to brownish orange lamellae, a brown stipe not discoloring on bruising, indistinct odour and taste, and acyanophilous ellipsoid to oblong-ellipsoid narrower basidiospores (4.5–6 × 3–4 μm, Q = 1.43–1.83, Qm = 1.59) with a very minute verrucose ornamentation; C. swetha K.N.A. Raj & Manim. (in Latha et al. 2016: 139) is also slender tricholomatoid, and differs by numerous characters such as the basidiomes that are whitish overall and not discolouring anywhere, with a velutinous pileus, indistinct odour and taste, quite smooth, 4–6 × 3–4 μm (Q = 1–2, Qm = 1.52) basidiospores, and a trichoderm-type pileipellis.

Figures

FIGURE 3. Calocybella dominicana. Fresh basidiomes (holotype, JBSD 126507). Scale bar: 10 mm. Picture by C. Angelini.

FIGURE 4. Calocybella dominicana. Microscopic features (holotype). a Clamp-connection b–e Basidiospores f Pileipellis g Hymenium and basidiospores. a–b, d, f–g (in ammoniacal Congo Red); c–e (phase contrast microscopy). Scale bars: a = 3μm; b–e = 6μm; f = 10μm; g = 10.5 μm. Pictures by C. Angelini.

FIGURE 5. Calocybella dominicana. Basidiospores (isotype, AH 46062). Scale bars = 1 μm. Scanning electron micrographs by G. Moreno.