Hygrocybe snigdha K. P. D. Latha & P. Haridev, 2023

Deepna Latha, K. P., Haridev, P., Anil Raj, K. N. & Manimohan, Patinjareveettil, 2023, A new species of Hygrocybe (Hygrophoraceae, Agaricales) from Kerala State, India, Phytotaxa 622 (1), pp. 63-74 : 67-71

Hygrocybe snigdha K. P. D. Latha & P. Haridev sp. nov. Figs. 1–2

MycoBank no.: MB 849120

Diagnosis:— Characterized by small basidiocarps, a deep red pileus with a distinct, orange-white margin and a strongly viscid surface, free lamellae with a fimbriate, white or reddish-white edge, a slightly translucent stipe with a subviscid and pruinose surface, dimorphic basidiospores and basidia, a lamella-edge with abundant pseudocystdia and an ixocutis-type pilei- and stipitipellis. Differs from H. hypohaemacta in having smaller basidiocarps with a nonhygrophanous pileus, pale red lamellae with a white or reddish-white edge, reddish to orange white stipe, a sterile lamella-edge, a subregular lamellar trama, and different nrITS and nrLSU sequences.

Type:— INDIA. Kerala State: Malappuram District, Calicut University Botanical Garden , 11°08’01.8”N 75°53’26.5”E, 02 November 2022, P. Haridev DKP-SERB95 (holotype CALI!). GenBank accessions: nrITS: OR125065 and nrLSU: OR127148 .

Etymology:— snigdha (Sanskrit) , viscid; refers to the viscid basidiocarps of this species.

Description:— Basidiocarps small. Pileus 4–13 mm diam., paraboloid or obtusely conical or at times hemispherical when young, becoming convex or plano-convex without an umbo or a depression at the center with age; surface deep red or vivid red (10C8, 11A8/OAC607, OAC614) all over with an orange white (5A2/OAC515) margin, not hygrophanous, strongly viscid all over, glabrous, translucent-striate towards the margin; margin incurved when young, becoming straight with age, entire or slightly wavy. Lamellae free, subdistant, pale red (10A3/OCA501), up to 2 mm wide, with lamellulae in 1–3 tiers; edge fimbriate, white or reddish-white (9A2/OCA550). Stipe 5–25 × 1–2 mm, central or rarely slightly eccentric, terete, equal when young, equal or slightly tapering towards the apex at maturity, cartilaginous, solid; surface red (10B6, 10A6/OAC574) all over when young, becoming dull red (10C4/OAC561) towards the apex, orange white (5A2/OAC515) towards the base at maturity, somewhat translucent, subviscid to tacky all over, minutely pruinose all over; base slightly enlarged. Context soft, up to 1 mm wide, pinkish white (10A2/ OCA501). Odor and taste not distinctive.

Basidiospores dimorphic; macrospores 8–10 × 5–8 (8.7 ± 1.0 × 6.0 ± 0.9) µm, Q = 1.1–1.7, Qm = 1.5, broadly ellipsoid, inamyloid, thin- to slightly thick-walled, hyaline, occasionally with oleaginous contents; microspores 4–5 × (3)4–5 (4.3 ± 0.6 × 3.9 ± 0.6) µm, Q = 1–1.7, Qm = 1.3, subglobose or ellipsoid, inamyloid, thin- to slightly thick-walled, hyaline, with oleaginous contents. Basidia dimorphic; macrobasidia 34–44 × 7–11 µm, clavate, thin-walled or thin- to slightly thick-walled towards the apex, hyaline or at times with some contents, 2-, 4-spored; sterigmata up to 3 µm long; microbasidia 23–28 × 6–9 µm, narrowly clavate or clavate, rarely flexouse, thin-walled or thin- to slightly thick-walled towards the apex, hyaline or at times with some contents, 1-, 2-, 4-spored; sterigmata up to 5 µm long. Pleurocystidia absent. Lamella-edge sterile with cheilocystidia as pseudocystidia originating from the tramal hyphae. Pseudocystidia 18–55 × 3–6 µm µm, abundant, narrowly clavate, narrowly cylindrical or flexouse, mostly septate, occasionally with bifurcations, thin-walled, hyaline with oleaginous contents. Lamellar trama subregular; hyphae 5–18 µm wide, thin-walled, hyaline. Pileipellis an ixocutis occasionally disrupted with erect and semi-erect, narrow hyphae; hyphae 2–6 µm wide, thin-walled, hyaline or with a pale yellowish wall pigment. Pileus trama subregular; hyphae 3–14 µm wide, thin-walled, with a pale yellowish brown plasmatic pigment. Stipitipellis an ixocutis composed of parallel to slightly interwoven, hyphae; hyphae 2–7 µm wide, thin- to slightly thick-walled, hyaline or with a pale yellowish plasmatic pigment. Clamp connections observed on all hyphae.

Habit and Habitat:— On soil, scattered or in small groups.

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

Additional specimens examined:— INDIA. Kerala State: Malappuram District, Calicut University Botanical Garden , 11°08’01.8”N 75°53’26.5”E, 03 December 2022, P. Haridev DKP-SERB116 ( CALI) ; 16 August 2023, P. Haridev DKP-SERB169 ; 17August 2023, P. Haridev DKP-SERB170 ; 22 September 2023, P. Haridev DKP-SERB189; Calicut University Campus , 11°08’03.0”N 75°53’19.0”E, 27 September 2023, P. Haridev DKP-SERB192. GenBank accessions: nrITS: OR125067 and nrLSU: OR127214 .

Figures

FIGURE 1. A–D: Hygrocybe snigdha (DKP-SERB95 (CALI), holotype). A–D. Basidiocarps in their natural habitat. Scale Bar: A–D = 10 mm.

FIGURE 2. A–G. Hygrocybe snigdha (DKP-SERB95 (CALI), holotype). A. Microspores. B. Macrospores. C. Microbasidia. D. Macrobasidia. E. Pseudocystidia. F. Pileipellis. G. Stipitipellis. Scale Bars: A–E = 10 µm; F–G = 20 µm.