Coprinopsis squamulosa 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 : 155-156

Coprinopsis squamulosa K. G. G. Ganga, Manim. & K. P. D. Latha. , sp. nov. Fig 2. A–M

MycoBank MB 845756

Etymology:—The specific epithet refers to the squamulose pileus surface of this species.

Diagnosis:—Floccose pileus with dark brown squamules at center, ovoid to ovo-ellipsoid basidiospores with a wide and central germ-pore, 4–5 pseudoparaphyses surrounding each basidium, and finely encrusted pleurocystidia. Differs from closely related species, C. kubickae in having larger basidiocarps, paraboloid to cylindrical pileus with recurved and scattered squamules on and around center, smaller basidiospores, and distinctive nrITS and nrLSU sequences.

Holotype:— INDIA. Kerala State: Kozhikode District, Calicut University Botanical Garden , 11°08’02.0” N 75°53’29.0” E, 12 June 2019, K. G. Greeshma Ganga G297 ( CALI). GenBank accessions: OP549278 (nrITS), OP549708 (nrLSU).

Description:— Basidiocarps small, fragile. Pileus 7–15 × 4–12 mm when young, finally 10–24 mm diam., initially paraboloid to cylindrical, expanding to plano-convex with age; surface with brown (6E6/OAC701) velar squamules all over when young, at maturity the squamules becoming dark brown (6F6/OAC698) at the center and whitish elsewhere, initially completely covered with appressed-squamules, at maturity with recurved squamules scattered on and around the center and floccose elsewhere, strongly deliquescent; margin initially straight, becoming upturned with age. Lamellae not observed due to deliquescence, initially white, becoming black at maturity. Stipe 20–55 × 2–3 mm, central, tapering towards the apex, hollow; surface white, smooth, slightly fibrillose towards the base; base slightly enlarged, often with a distinct basal disc. Odor and taste not distinctive.

Basidiospores (n = 40) (7)8–9 × 5–7 × 5–6 µm, on an average 8.6 × 5.2 × 5.0 µm, Q 1 = 1.1–1.6, Q 1avg = 1.3, Q 2 = 1.3–1.8, Q 2avg = 1.4, lenticular, ovoid to ovo-ellipsoid with a rounded base and somewhat truncate apex in face view, amygdaliform to subamygdaliform in side view, dark brown, thick-walled, with a central germ-pore up to 2.5 µm wide. Basidia 12–25 × 9–10 µm, clavate, hyaline, slightly thick-walled, surrounded by 4–5 pseudoparaphyses, 4-spored; sterigmata up to 5 µm long. Pleurocystidia 78–95 × 20–38 µm, abundant, cylindrical to sublageniform with short finger-like projections at the apex, finely encrusted, hyaline, thick-walled. Lamella-edge heterogeneous. Cheilocystidia 46–65 × 22–27 µm, ellipsoid to cylindrical often with finger-like projections at the apex, hyaline, thinwalled. Pileipellis a cutis composed of elongate, parallelly arranged hyphae with loosely bound, narrow and inflated velar elements; hyphae 3–12 µm wide, hyaline, thick-walled; narrow velar elements 4–14 µm wide, cylindrical to subcylindrical or coralloid, regularly branched, diverticulate, hyaline, thin-walled; inflated velar elements 5–10 µm wide, frequently coralloid, pale brown to brown, thick-walled (up to 3 µm thick). Stipitipellis a cutis finely overlaid with velar elements; hyphae 10–32 µm wide, hyaline, thin-walled; velar elements similar to those on the pileipellis, 2–6 µm wide, hyaline, slightly thick-walled. Clamp connections observed only in velar elements.

Habitat:—Scattered or in small groups, on decaying bamboo litter.

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

Comments:—The characters such as smaller basidiocarps, cylindrical to sublageniform pleurocystidia, and a cutis-type pileipellis with coralloid, brown velar elements lead C. sqaumulosa to the section Coprinopsis . Coprinopsis kubickae shows some similarity to C. sqaumulosa in having floccose velar remnants on pileus, a stipe with a white basal disc, and a habitat on decaying monocot plant remnants. However, C. kubickae differs from C. sqaumulosa in having smaller basidiocarps, subglobose to ovoid pileus with flocculose velar remnants, larger basidiospores (7–11.5 × 6–10.5 µm) with a central to eccentric and narrow germ-pore (1.3–1.6 µm), 5–8 pseudoparaphyses surrounding each basidium, a hymenium with larger pleuro- (55–200 × 12–28 µm) and cheilocystidia (35–120 × 11–28 µm), and thinwalled velar elements on the pileipellis.

Coprinopsis friesii (Quélet 1872: 129) P. Karst (1881: 27) , common in Europe and also reported from Canada, South America, and North Africa ( Uljé 2005), resembles C. sqaumulosa in having similar color of basidiocarps, thickwalled and pale yellow velar elements on pileipellis, almost similar-sized basidiospores (6–9.5(11) × 5.5–7(8.5) µm), pleuro- and cheilocystidia with finger-like projections at the apex, and occurrence on decaying monocot plant remnants. However, C. friesii has basidiocarps with a smaller (up to 15 mm), conical pileus, each basidium surrounded by 5–7 pseudoparaphyses, and red brown basidiospores with a narrow (1.5 µm) germ-pore. Coprinopsis pseudofriesii (Pilát & Svrček 1967: 140) Redhead, Vilgalys & Moncalvo (2001: 230) , widespread in Europe ( Uljé 2005) shows close similarity with C. sqaumulosa in having similar size and color of the basidiocarps, basidiospores with a central germpore, and pleuro- and cheilocystidia with finger-like projections. Coprinopsis pseudofriesii , however, is distinguished from C. sqaumulosa in having basidiocarps with a conical pileus, each basidium surrounded by 4–7 pseudoparaphyses, red brown basidiospores with a rounded apex and narrow germ-pore (1.3–1.6 µm), a pileipellis with narrow velar elements, and growth on a different substratum.

Comparison of the nrITS and nrLSU sequences generated from C. sqaumulosa with those sequences available in the GenBank database revealed that it has distinct sequences. A BLASTn search with the nrITS (675 bp) sequence of C. sqaumulosa showed an unidentified Coprinopsis species BLBS 104 ( MK843958 ) as the closest hit with 97.35% sequence similarity. Coprinopsis urticicola ( HQ847101 : 99.12%) was resulted as the closest hit in a BLASTn search with nrLSU sequence (920 bp). Coprinopsis urticicola differs from C. sqaumulosa in having a pileus with woolly-hairy velar scales, subglobose to ellipsoid basidiospores with a narrow (1–1.5 µm) germ-pore, and thin-walled, encrusted velar elements on the pileipellis.

The phylogram inferred from the nrITS-based ML analysis ( Fig. 3 ) showed that these two new species, C. minuta and C. squamulosa were nested within a monophyletic group representing the sect. Coprinopsis . Within this clade, three collections of C. urticicola ( MH748639 , HQ847015 , MW915588 ), one unidentified species, ‘Basidiomycota species PCT.10’ and two collections of C. minuta together formed a distinct group with full (100%) bootstrap support. Inside this group, C. minuta was shown to be a distinct lineage sister to ‘Basidiomycota species PCT.10’ with maximum bootstrap support (100% BS). The other species, C. squamulosa was found clustered with an unnamed species from Brazil, Coprinospis species BLBS104 with strong bootstrap support (96% BS).

Figures

FIGURE 2. A–M: Coprinopsis squamulosa (G297 (CALI), holotype). A–C. Basidiocarps; D. Basidiospores; E. Basidia; F. Pseudoparaphyses; G–H. Cheilocystidia; I–K. Pleurocystidia; L. Pileipellis; M. Velar elements on the pileipellis. Scale bars: A–C = 10 mm; G, I, J & L = 50 µm; D–F, H, K & M = 20 µm.

FIGURE 3. ML phylogram based on the nrITS sequence data matrix depicting the position of C. minuta and C. squamulosa in sect. Coprinopsis. Values at nodes indicate the bootstrap support. Bootstrap values ≥50% are shown.