Psathyrella cladii-marisci Sicoli, NG Passal., De Giuseppe, Palermo & Pellegrino

Sicoli, Giovanni, Passalacqua, Nicodemo G., De Giuseppe, Antonio B., Palermo, Anna Maria & Pellegrino, Giuseppe, 2019, A new species of Psathyrella (Psathyrellaceae, Agaricales) from Italy, MycoKeys 52, pp. 89-102 : 89

Psathyrella cladii-marisci Sicoli, NG Passal., De Giuseppe, Palermo & Pellegrino sp. nov. Figs 1, 2, 3

Etymology.

The specific epithet derives from Cladium mariscus , the name of the plant where it was first detected.

Diagnosis.

Similar to P. thujina from which it differs by showing a larger pileus (about 40% larger), a wider range of spore length, versiform cheilocystidia and basidiomes occurring in spring.

Holotype.

Italy. Calabria, Cosenza, Rende, Orto Botanico Università della Calabria. 39°21'25.05"N, 16°13'44.57"E, 220 m a.s.l., marsh at the base of cut culms of a Cladium mariscus (L.) Pohl plant, transplanted from Lago dell’Aquila (Laureana di Borrello, Reggio Calabria, southern Italy) at the corner of a concrete tank maintained full of water, 10 April 2018, Antonio Biagio De Giuseppe & Giovanni Sicoli (CLU F302).

Description.

Habit psathyrelloid. Pileus up to 3.5 cm diam., conical-convex when young, hemispheric to applanate at maturity, with a deeply striate margin, hazelnut in colour, turning to pale beige when dry. Pileipellis with evident concentric arachnoid fibrils of velar origin, whitish and easily removable, often exceeding the cuticle margin. Lamellae distant, ventricose, adnate, intermingled with numerous lamellulae, initially pale pink, then intensely brown-purplish. Lamella edge whitish with numerous sphaeropedunculate cells. Stipe, very fragile, cylindrical, white, exannulate with a diffuse fibrillosity especially on the basal surface, apical surface pruinose. Basidiospores 7.2-11.8 × 4.3-6.0 µm (n = 100), ellipsoid to ovoid-ellipsoid, with a thick and smooth wall, adaxially flattened with a central 2µm-wide germ pore and a distinct hilar appendix. Spore-print dark brown. Basidia clavate, 4-spored. Cheilocystidia versiform, often utriform, seldom cylindrical to clavate. Pleurocystidia utriform-shaped. Mycelium septate and clamped. Context with apparently no smell, taste mild.

Habit, habitat and distribution.

In small groups (gregarious), on the culm remnants of Cladium mariscus . So far, known only from the type locality.