Coprinopsis minuta K. G. G. Ganga, Manim. & K. P. D. Latha., 2022

Greeshma Ganga, K. G., Manimohan, Patinjareveettil & Deepna Latha, K. P., 2022, Two new species of Coprinopsis from Kerala State, India, Phytotaxa 575 (2), pp. 149-158 : 151-155

Coprinopsis minuta K. G. G. Ganga, Manim. & K. P. D. Latha. , sp. nov. Fig 1. A–G

MycoBank MB 845755

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

Diagnosis:—Very small basidiocarps, floccose velar remnants on pileus, subglobose to ovoid basidiospores with a rounded base, 5–6 psuedoparaphyses surrounding each basidium, and clavate pleurocystidia with a lobed apex. Differs from C. urticicola in having floccose velar remnants on pileus, stipe with a somewhat marginate bulbose base, basidiospores with a round base, 5–6 psuedoparaphyses surrounding each basidium, clavate pleurocystidia with apical lobes, smooth velar elements on the pileipellis, and distinctive nrITS and nrLSU sequences.

Holotype:— INDIA. Kerala State: Kozhikode District, Calicut University Campus, 11°07’56.5” N 75°53’32.1” E, 12 August 2016. K. G. Greeshma Ganga G63 ( CALI). GenBank accessions: OP 549280 (nrITS), OP 549279 (nrLSU).

Description:— Basidiocarps very small, fragile. Pileus 3–6 mm diam. when mature, initially ovoid, paraboloid or cylindrical, then expanding to broadly paraboloid to convex; surface pure white when young, becoming orange gray (5B2/OAC760) with white velar remnants, initially completely covered with a thick floccose veil that later splitting into superficial, velar patches all over; margin initially incurved to straight, becoming decurved or slightly revolute, often fissile, deliquescent at maturity. Lamellae free, crowded, initially white, becoming dark brown (7F7/OAC733) with age; edge not observed due to deliquescence. Stipe 11–15 × 0.5–1 mm, central, tapering towards the apex, hollow; surface white, finely squamulose all over, slightly floccose towards the base; base somewhat marginate-bulbous with profuse basal mycelium. Odor and taste not distinctive.

Basidiospores (n = 80) 6–8(9) × 5–7.5 × 5–6 µm, on an average 7.22 × 6.2 × 5.47 µm, Q 1 = 1–1.4, Q 1avg = 1.17, Q 2 = 1–1.4, Q 2avg = 1.23, lenticular, subglobose to ovoid with rounded base and apex, ellipsoid in side view, brown, thickwalled, with a central germ-pore up to 2 µm wide. Basidia 15–20 × 6–9 µm, clavate to pedicellate-clavate, hyaline, slightly thick-walled, surrounded by 5–6 pseudoparaphyses, 4-spored; sterigmata up to 3 µm long. Pleurocystidia 13–22 × 7–15 µm, broadly clavate with 2–3 lobed apex, hyaline, thin-walled. Lamella-edge not observed due to deliquescence. Cheilocystidia not observed. Pileipellis a cutis frequently disrupted by clumps of velar elements; hyphae 3–5 µm wide, subcylindrical, hyaline, thin-walled; velar elements 17–50 × 5–15 µm, branched, coralloid, hyaline, slightly thick-walled. Stipitipellis a cutis disrupted with velar elements; hyphae 3–8 µm wide, hyaline, slightly thick-walled; velar elements 5–14 × 2–8 µm, almost similar to the velar elements on the pileipellis, hyaline, slightly thick-walled. Clamp connections not observed on any hyphae.

Habitat:—In small groups or scattered, on decaying twigs or rotten fruit pods of rubber tree ( Hevea brasiliensis ).

Geographical distribution range:—Known only from the type locality in Kerala State, India.

Additional specimens examined:— INDIA. Kerala State: Kozhikode District, Calicut University Campus , 11°07’56.5” N 75°53’32.1” E, 23 July 2016, K. G. Greeshma Ganga G23 ( K. P. Deepna Latha personal herbarium). GenBank accessions: OP 549038 (nrITS), OP 549277 (nrLSU) .

Comments:—Smaller basidiocarps, deliquescent lamellae, subglobose basidiospore and a cutis-type pileipellis with colorless and coralloid velar elements place C. minuta in the sect. Coprinopsis . Coprinopsis urticicola (Berkeley & Broome 1861: 376) Redhead, Vilgalys & Moncalvo (2001: 232) , a species originally described from North America ( Uljé 2005) and also reported from East Africa ( Pegler 1977), Europe and Iran ( Asef et al. 2015), seems to be close to C. minuta in having almost similar-sized basidiospores (5.5–9 × 4.5–6.5 µm), coralloid velar elements on the pileipellis, absence of clamp connections, and a lignicolous habitat. However, C. urticicola differs from C. minuta in having a pileus with woolly-hairy velar scales, basidia surrounded by 5–8 psuedoparaphyses, basidiospores with a conical base, utriform to subcylindrical pleurocystidia, and a pileipellis with strongly encrusted velar elements. Coprinopsis kubickae (Pilát & Svrček 1967: 142) Redhead, Vilgalys & Moncalvo (2001: 229) , reported from Europe ( Uljé 2005), shares some similarities with C. minuta in having basidiocarps with an ochre brown to grayish pileus, stipe with an enlarged base, and coralloid velar elements on pileipellis. However, C. kubickae has minute, flocculose velar remnants on pileus, larger basidiospores (7–11 × 6–10 µm) with central to eccentric germ-pore and conical base, 5–8 psuedoparaphyses surrounding each basidium, a hymenium with utriform to subcylindrical pleurocystidia, clamped hyphae, and a habitat on soil ( Uljé 2005).

In a BLASTn search using the nrITS (676 bp) sequence, the closest hit was an unidentified Basidiomycota species PCT.10 (HQ248225: 99.70%) followed by C. urticicola ( MH748639 : 95.96 %). While using the nrLSU (956 bp) sequence, C. urticicola ( HQ847101 : 99.36 %) was resulted as the closest hit.

Figures

FIGURE 1. A–G: Coprinopsis minuta (G63 (CALI), holotype).A. Basidiocarps; B. Basidiospores; C. Basidium; D. Pseudoparaphyses; E. Pleurocystidia; F. Pileipellis; G. Velar elements on the pileipellis. Scale bars: A = 5 mm; B–E = 20 µm; F & G = 50 µm.