Pseudosperma­­indicum­­ K. P. D. Latha, P. Haridev & Manim, 2023

Deepna Latha, K. P., Haridev, P., Anil Raj, K. N. & Manimohan, Patinjareveettil, 2023, -- Pseudosperma- - indicum- - sp. -- nov. -- (Inocybaceae, Agaricales) -- from India, Phytotaxa 620 (1), pp. 47-58 : 51-54

Pseudosperma­­indicum­­ K. P. D. Latha, P. Haridev & Manim . sp. nov. Figs. 1–2

MycoBank no.: MB 849434

Diagnosis:— Characterized by a dark brown pileus with an appressed-fibrillose to rimose surface; an appressed- and twisted-fibrillose stipe with a pruinose apex; smooth basidiospores; abundant, versiform cheilocystidia with yellowish amorphous contents; a disrupted cutis-type pileipellis with distinct supra- and subpellis regions and versiform caulocystidia restricted to the stipe apex. Differs from P. transiens in having smaller basidiocarps with a plano-convex or applanate pileus, white to orange-gray lamellae, a shorter, grayish red or orange-gray stipe, slightly smaller basidiospores, a lamella-edge devoid of paracystidia, a subpellis of the pileipellis with dark brown spiral encrustations and smaller caulocystidia.

­­ Type:— INDIA. Kerala State: Ernakulam District, Perumbavoor, Iringolkav Sacred Grove , 10°06’29.8”N 76°30’08.1”E, 15 November 2022, P. Haridev DKP-SERB109 (holotype CALI!) .

­­ Etymology:— The epithet ‘ indicum’ refers to India, where this species was first discovered.

­­ Description:— Basidiocarps small. Pileus 16–40 mm diam., hemispherical or paraboloid when young, becoming plano-convex or applanate with a broad umbo at the center surrounded by a shallow depression with age; surface initially dark brown (8F8/OAC635) at the center and on the fibrils, grayish red (8D5/OAC726) elsewhere, becoming reddish brown or dark brown or (8 E8, 8 F8/OAC719) at the center and on the fibrils, grayish red or brownish orange (8C4, 7C4/OAC635, OAC666) elsewhere at maturity, appressed-fibrillose all over when young, becoming somewhat smooth at the center, radially rimose exposing paler tissue beneath towards the margin with age; margin initially incurved, becoming straight or slightly reflexed at maturity, wavy, fissile. Lamellae up to 3 mm wide, adnexed or narrowly adnate, close to moderately crowded, white to orange gray (5B2/OAC683) when young, with 2–3 series of lamellulae; orange gray (6B2/OAC675) at maturity, edge entire to the naked eye, fimbriate under a lens, whitish. Stipe 45–80 × 3–5 mm, central or slightly eccentric, terete, equal or slightly tapering towards the apex, fibrous, solid; surface initially white all over, becoming grayish red or orange gray (8C3, 6B2/OAC620, OAC668) all over at maturity, appressed- and twisted-fibrillose all over, densely pruinose towards the apex; base sub-bulbous to bulbous with a whitish mycelium. Odour and taste indistinctive.

Basidiospores 8–10(11) × 4–6 (9.2 ± 0.9 × 5 ± 0.6) µm, Q = 1.5–2, Qm = 1.8, smooth, ellipsoid or oblong in frontal view, amygdaliform or phaseoliform in side view, thick-walled (up to 0.9 µm thick), pale yellowish brown. Basidia 11–27 × 8–11 µm, clavate, slightly thick-walled (up to 0.5 µm thick), hyaline, 2-, 4-spored; sterigmata up to 3 µm long. Pleurocystidia absent. Lamella-edge sterile with clusters of cheilocystidia. Cheilocystidia 23–53 × 9–18 µm, abundant, versiform, cylindrical, utriform or broadly clavate, sometimes septate, occasionally with a capitate apex, thin- to slightly thick-walled (up to 0.9 µm thick), hyaline or with yellowish amorphous contents all over, especially at the apex. Lamellar trama subregular; hyphae 5–30 µm wide, thin- to slightly thick-walled (up to 0.5 µm thick), hyaline. Pileus trama subregular with narrow and inflated hyphae; hyphae 5–35 µm wide, thin- to slightly thick-walled (up to 0.5 µm thick), hyaline or with a pale yellowish plasmatic pigment. Pileipellis a disrupted cutis with distinct supra- and subpellis regions, occasionally suprapellis with scattered or small patches of ascending hyphae; suprapellis up to 30 µm thick, composed of 7–8 layers of loosely arranged hyphae (48–135 × 6–12 µm), thin- to slightly thick-walled (up to 0.7 µm thick), hyaline or with a pale-yellow wall pigment; subpellis made up of parallel, compact hyphae (6–19 µm wide), slightly thick-walled (up to 0.8 µm thick), with a yellowish brown wall pigment and dark brown spiral encrustations. Stipitipellis a cutis disrupted by isolated or small bunches of caulocystidia confined to the apex of the stipe; hyphae 4–12 µm wide, slightly thick-walled (up to 0.7 µm thick), hyaline or with a pale-yellow wall pigment and hyaline encrustations. Caulocystidia 18–46 × 13–28 µm, abundant, versiform: obovoid, cylindrical, narrowly clavate or clavate, rarely septate, slightly thick-walled (up to 0.9 µm thick), hyaline. Oleiferous hyphae (4–7 µm wide) present in stipe and pileus trama. Clamp connections observed on all hyphae.

­­ Habit­­and­­Habitat:— On soil around Vateria indica (Dipterocarpaceae) trees, solitary or in small groups.

­­ Geographical­­distribution­­range:— Known only from the type locality (Kerala State, India) .

­­ Additional­­specimens­­examined:— INDIA. Kerala State: Ernakulam District, Perumbavoor, Iringolkav Sacred Grove , 10°06’29.8”N 76°30’08.1”E, 25 September 2022, P. Haridev DKP-SERB82 .

Figures

FIGURE 1. A–H: Pseudosperma­­indicum. A. Basidiocarps in their natural habitat. B. Basidiospores, C. Basdium. D. Cheilocystidia. E. Pileipellis. F. Stipitipellis. G–H. Caulocystidia. Scale Bars: A = 10 mm, B–D, G–H = 10 µm, E = 20 µm, F = 40 µm.

FIGURE 2. A–G. Pseudosperma­­indicum. A. Basidiocarps. B. Basidiospores. C. Basidia. D. Cheilocystidia.E. Pileipellis.F. Stipitipellis. G. Caulocystidia. Scale Bars: A = 10 mm, B–D, G = 10 µm, E–F = 20 µm.