Parasola psathyrelloides K. G. G. Ganga & Manim., 2019

Greeshma Ganga, K. G. & Manimohan, Patinjareveettil, 2019, Parasola psathyrelloides (Psathyrellaceae), a new species from Kerala State, India, Phytotaxa 405 (5), pp. 255-262 : 257-259

Parasola psathyrelloides K. G. G. Ganga & Manim. , sp. nov. ( Fig. 1. A–L ).

MycoBank MB 830265

Etymology:—The specific epithet refers to the psathyrelloid basidiocarps of this species.

Diagnosis:—Characterized by psathyrelloid basidiocarps, finely sulcate-striate pileus, adnate lamellae, absence of pleurocystidia, and ovoid to ovo-ellipsoid basidiospores with 3–4 rounded angles in face view. Differs from P. conopilea in having smaller basidiocarps, the presence of pseudoparaphyses surrounding the basidia, smaller and rounded angular basidiospores with a smaller, central germ-pore, shorter sclerocystidia on pileipellis, and distinctive ITS and nLSU sequences.

Holotype:— INDIA. Kerala State: Kollam District, Thenmala Forest , 30 July 2017, K. G. Greeshma Ganga G191 ( CAL 1753 ). GenBank accessions: ITS ( MK682756 ) and nLSU ( MK682754 ).

Description:— Basidiocarps small, psathyrelloid, delicate, not deliquescent, not collapsing. Pileus 2–9 × 1.5–8 mm when young, finally 16–20 mm diam, initially hemispherical to somewhat convex, expanding to almost conicoconvex; surface light brown (6D8/OAC706) when young, brownish orange (6C6/OAC278) to light brown (6D6/ OAC727) all over when mature, glabrous, initially translucent-striate, becoming finely sulcate-striate up to the center, finely tuberculate-punctate when mature, when young often with brown hairs that disappear as the pileus matures; margin straight, entire. Lamellae adnate, L = 19–20, almost close to close, initially white, becoming grayish brown (7E3), lamellulae in 1–2 tiers; margin eroded, becoming paler when mature. Stipe 43–52 × 1.5–2 mm, central, equal, smooth, hollow, white to off-white; base slightly enlarged, when young often with abundant hairs that disappear during the development of the stipe. Velar elements absent. Odor and taste not distinctive. Spore print not obtained.

Basidiospores (8)9–12 × 7–9 × 6–7(8) μm, on an average 10.6 × 8.0 × 6.8 μm, Q 1 = 1.12–1.50, Q 1avg = 1.34, Q 2 = 1.28–2.0, Q 2avg = 1.54, lenticular, ovoid to ovo-ellipsoid in face view, often with 3–4 rounded angles, oblong to ellipsoid in side view, dark brown to black, thick-walled, with a central germ pore up to 1 μm wide. Basidia 24–38 × 9–11 μm,

clavate to pedicellate-clavate, hyaline, thin-walled, surrounded by 4–5 pseudoparaphyses, 4-spored; sterigmata up to 5 μm long. Lamellar edge sterile. Cheilocystidia abundant, 27–47 × 18–23 μm, versiform: globose, subglobose,

utriform, or lageniform, often with a short pedicel, hyaline. Pleurocystidia absent. Pileipellis hymeniform, composed of clavate elements, 27–43 × 7–23 μm, mostly hyaline, often with an intraparietal yellow pigment towards the base of the structure, mixed with sclerocystidia; sclerocystidia 103–250 × 5–7.5 μm, brown, thick-walled. Stipitipellis a cutis often with abundant, 300–700 μm long, thick-walled, brown hairs restricted towards the base (ozonium); hyphae

3–5 μm wide, thin-walled, hyaline or with pale yellow intraparietal pigment. Clamp connections observed only on the hyphae of the stipitipellis.

Habitat:—On decaying twigs on the forest floor, in small groups.

Geographical distribution range:—Known only from three localities in Kerala State, India.

Additional specimens examined:— INDIA. Kerala State: Kozhikode District, Peruvannamuzhi Forest, 28

September 2017, K. G. Greeshma Ganga G221 (AMH 10119). GenBank accessions: ITS (MK682752) and nLSU

(MK682759); Wayanad District , Muthanga Forest, 05 July 2017, K. G. Greeshma Ganga G172 ( AMH 10120 ) .

GenBank accessions: ITS (MK682758) and nLSU (MK682755).

Figures

FIGURE 1. A–J: Parasola psathyrelloides. A–C. Basidiocarps; D. Basidiospores; E–G. Cheilocystidia; H. Pseudoparaphyses (white arrows) surrounding basidia (black arrows); I. Basidia; J. Pileipellis elements; K. Hairs on stipe base; L. Sclerocystidia on pileus. Scale bars:A–C = 10 mm; D, E, F, G & I = 20 μm; H, J, K & L = 50 μm. Photographs by: K. G. Greeshma Ganga.