Coprinopsis fulva Sch, 2023

Schünemann, Bárbara Letícia Botura, Westphalen, Mauro, Díazvalderrama, Jorge Ronny, Aguilar, Vilma & Silveira, Rosa Mara Borges Da, 2023, Coprinopsis (Psathyrellaceae, Agaricales) in the Neotropics: three new species and a new combination, Phytotaxa 585 (2), pp. 113-134 : 126-127

Coprinopsis fulva Sch ̧nemann, Diaz Val., Aguilar& R.M.Silveira, sp. nov.

FIG. 4

Mycobank: 846928

Typification: — BRAZIL. Rio Grande do Sul: Derrubadas, Parque Estadual do Turvo , gregarious on decayed tree, 27°08’22.5”S, 53°52’57.3”W, 30 October 2017, B. L. B. Schünemann 113 (holotype ICN 200445 ), Gen Bank accessions: MK843961 , ON640622, ON653381, ON707699 .

Diagnosis: —Pileus medium grey with white to greyish green umbo, brown veil in fibrillose patches, loosely attached, clavate with mucronate apex pleurocystidia, diverticulate, thick-walled and yellowish veil elements.

Etymology: —The name fulvus refers to the yellowish brown color of veil elements.

Description: —Pileus prior to expansion 3–5 × 2–3 mm, globose becoming ovoid, greenish grey (1B2), with brown (6E4) veil adhered in scales; 9–11 × 5–9 mm wide when expanded, ovoid to parabolic then applanate, plicate, medium grey (1E1) and the umbo white (1A1) to greyish green (1B2), fibrillose veil in patches all over the pileus, brown (6E4) and powdery towards margin, white (1A1), loosely attached, 15 × 2 mm when revolute, becoming translucid. Lamellae adnate, close, at young stage, pale grey (1A2) to dark brown (7F6), deliquescent, pleurocystidia visible with a magnifying glass. Stipe 10–30 × 1–2 mm, central, equal, fistulose, yellowish white (1BA). Annulus absent.

Basidiospores 6–8 × 5–6 × 5.5–6.5 μm, Q= 1.07–1.33, Qav = 1.22; broadly ellipsoid in frontal view, light grey to brown in KOH, guttulate, thick-walled, smooth; apiculus visible; germ pore eccentric, covered with a hyaline cap. Basidia dimorphic, clavate 12–16 × 6–7 μm and long clavate 19–24 × 7–8 μm, hyaline, 4-spored, surrounded by 3–4 pseudoparaphyses. Cheilocystidia absent. Pleurocystidia 62–133 × 9–18 μm, clavate with mucronate apex, hyaline, thin-walled, abundant. Hymenophoral trama parallel to subparallel. Pileipellis a cutis with elongated hyphae, radially oriented, hyaline, anastomosing, thick-walled. Veil composed of branched and diverticulate elements, thin and thickwalled, brownish. Stipitipellis a cutis with elongated elements, hyaline. Clamp connections present.

Habitat and known distribution: —Growing gregarious in decayed branches of Semideciduous Seasonal Forest and endophyte of cultivated rice under flooded system; recorded from Parque Estadual do Turvo, Derrubadas (Rio Grande do Sul, Brazil) and Puerto Naranjitos locality (Amazonas, Peru).

Additional specimens examined: — Peru, Amazonas department, Utcumbamba province, Puerto Naranjitos locality, (S 05°49’7.6’’/ W 78°17’12.6’’), isolated from rice leaves, March 2021, leg. J. R. Díaz-Valderrama, INDES-VAR05 , GenBank accessions: ON640612, ON640624 .

Comments: —The main distinguishing features of Coprinopsis fulva are the greyish pileus with brown fibrillose veil in patches, becoming powdery to the margin; the adnate lamellae; clavate pleurocystidia with mucronate apex; thin to thick-walled diverticulate and branched veil elements with brownish coloration and lignicolous habitat ( FIG. 4 ).

Based on diverticulate and thick-walled veil elements, Coprinopsis fulva belongs to the section Alachuani ( Schafer 2010). In the phylogeny, C. fulva is included in the section / Coprinopsis ( Wächter & Melzer 2020) due the veil strongly developed, consisting of chains of diverticulate, thin and thick-walled, hyaline or brownish pigmented cells and clavate pleurocystidia.

Coprinopsis fulva is phylogenetically related to C. urticicola (Berk. & Broome) Redhead, Vilgalys & Moncalvo (2001: 232) in Redhead, Vilgalys, Moncalvo, Johnson & Hopple (2001), C. friesii (Quél.) P. Karst (1881: 27) and morphologically similar to C. caesia sp. nov. C. urticicola has free lamellae, subcylindrical to narrowly utriform and oblong pleurocystidia (40–70 x 10–15 μm), thin-walled veil elements and clamp connections absent (Asef et al. 2005). C. friesii has ovoid to slightly rhomboid basidiospores, oblong to narrowly conical pleurocystidia, strongly diverticulate thick-walled veil elements, growing in grasses ( Uljé 2005; Keirle et al. 2004).

Morphologically Coprinopsis fulva also is similar to C. caesia sp. nov. and other species included in / Coprinopsis clade. The veil elements are very important to distinguish these species, with C. fulva being unique in having both thin and thick-walled, yellowish brown, branched and diverticulate veil elements. In addition, it was found growing on decomposing wood.

Figures

FIGURE 4. Macroscopic details of Coprinopsis fulva (ICN 200445) a, b, c. basidiomata. Microscopic features d. basidiospores e. basidia f. pleurocystidia g. veil elements on the pileipellis. Scale bars: a, b, c. 10 mm d. 10 µm e. 20 µm f. 50 µm g. 20 µm. Photos: Bárbara Scḩnemann.