Crinipellis minima S. A. Sharafudheen, Manim. & K. P. D. Latha, 2023

Sharafudheen, Shahina A., Manimohan, Patinjareveettil & Deepna Latha, K. P., 2023, Two new species of Crinipellis (Marasmiaceae, Agaricales) from Kerala State, India, Phytotaxa 600 (4), pp. 219-229 : 223-225

Crinipellis minima S. A. Sharafudheen, Manim. & K. P. D. Latha , sp. nov. Fig. 2A–L

MycoBank no.: MB 847917

Etymology:— minima (L.) , small; refers to the very small basidiocarps of this species.

Diagnosis:—Differs from C. kisanganensis in having a smaller (up to 20 mm long) stipe covered with orange white, recurved squamules, a hymenium with pleurocystidia, and the lamellar trama with a dextrinoid central region.

Type:— INDIA. Kerala State: Thiruvananthapuram District, Neyyar Wildlife Sanctuary , 8°33’24.7” N 77°09’33.0” E, 22 October 2017, A. S. Shahina SA324 (holotype CALI!). GenBank accessions: nrITS: OQ617341 and nrLSU: OQ617343 .

Description:— Basidiocarps small. Pileus 3–4.5 mm diam., initially convex, becoming convex with a shallow central depression; surface initially dark brown (7F5/OAC700) all over with a darker center (7F8/OAC733), becoming dark brown (7F7/OAC720) at the center, light brown (7D5/OAC701) around it, grayish orange (5B3 to 5B5/OAC813 to OAC814) towards the margin, with brown (7E8/OAC700 or OAC701), radially appressed fibrils extending to the margin; margin straight, appendiculate. Lamellae free or at times adnexed, up to 1 mm wide, light orange white (5A2/OAC900), subclose, with lamellulae of 1 tier; edge torn under a lens, concolorous with the sides. Stipe 11−20 × 0.5–0.75 mm, central, terete, equal; surface initially pale yellow (4A3/OAC805) at the base and the apex and yellowish white (4A2/OAC900) in the middle, becoming light brown (6D4/OAC700) all over except at the apex where it is concolorous to the lamellae when mature, with orange white (5A2/OAC815), recurved squamules all over, densely so towards the base; base insititious. Rhizomorphs not observed. Context thin.

Basidiospores 9–10.5 × 4–5 (9.63 ± 0.51 × 4.4 ± 0.48) µm, Q = 1.9–2.5, Qm = 2.20, fusoid to ovo-ellipsoid, smooth, thin-walled, rarely slightly thick-walled, hyaline, inamyloid. Basidia 21–28 × 6–8 µm, clavate, 4-spored; sterigmata up to 3 µm long. Pleurocystidia scattered to rare, not observed in some lamellae, 19–31 × 5–9 µm, fusoid or clavate with a mucronate apex, at times with constrictions in the body, hyaline, thin- to slightly thick-walled. Lamella-edge heteromorphous with abundant cheilocystidia. Cheilocystidia 16–26 × 5–9 µm, resembling Siccus - type broom cells: broadly clavate to subcylindrical, hyaline, thin- to slightly thick-walled; apical appendages up to 8 µm long, often branched, subacute to obtuse, hyaline, thin- to slightly thick-walled, sometimes appendages reduced or with lobes. Lamellar trama subregular; hyphae 4–14 µm wide, thin- to slightly thick-walled (up to 1 µm thick), hyaline, central part of the trama weakly dextrinoid. Pileus trama subregular; hyphae 2–15 µm wide, thin-walled, hyaline, inamyloid. Pileipellis a hypotrichium composed of closely septate, inflated hyphae giving rise to suberect terminal hairs; hypotrichial hyphae 11–16 µm wide, thin- to slightly thick-walled, hyaline or pale yellow, hyphae brown at the central part of the trama in water and 5% KOH, sometimes with hyaline encrustations; hairs 46–438 × 4–7 µm, cylindrical or flexuous with subacute to obtuse apices, rarely with septa, often with a swollen base, light brown to brown or somewhat grayish in water and 5% KOH, dextrinoid, thick-walled (up to 1.5 µm thick). Stipitipellis similar to the pileipellis but with narrow hypotrichial hyphae and short hairs; hypotrichial hyphae 2.5–7 µm wide, thick-walled (up to 1 µm thick), yellowish brown to brown in water, turning greenish in 5% KOH. Stipitipellis hairs 55.5–252 × 5–11 µm, tapering towards the apex, hyaline or yellowish brown, septa not observed. Stipe trama dextrinoid. Clamp connections observed on all hyphae.

Habitat: — Scattered, on decaying dicotyledonous leaves and twigs.

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

Comments:—Small basidiocarps, a pileus with a central depression, a stipe without rhizomorphs, a hymenium with cheilo- and pleurocystidia, a weakly dextrinoid middle region of lamellar trama, pileipellis hyphae (hypotrichium) lacking discoloration in KOH and stipitipellis hyphae (hypotrichium) turning greenish in KOH are the characteristic features of this species. Pleurocystidia were found to be scattered or rare or absent in different specimens of the same collection. Crinipellis kisanganensis Antonín & Buyck (in Antonín 2012: 402), a species described from Congo and Zimbabwe ( Antonín 2012), is comparable to C. minima in having small basidiocarps, a pileus with a dark brown depressed center, basidiospores of almost similar size (8–10 × 3.5–4.75 µm), cheilocystidia of almost similar size ((12) 15–26 × 4.5–9 µm) and morphology and the pileipellis hairs not changing color in KOH. However, C. kisanganensis is distinct from C. minima in having a longer (up to 35 mm long) and laterally compressed stipe covered with dark brown hairs or grayish brown hairs, the absence of pleurocystidia and a dextrinoid middle region in the lamellar trama. There is no mention of the reaction of stipitipellis (hypotrichium) with KOH in that collection. Crinipellis dipterocarpi Singer (1942: 496) , a species originally described from Vietnam and later from Indonesia, Malaysia, Thailand ( Kerekes & Desjardin 2009) and Japan ( C. dipterocarpi f. cinnamomea Kerekes, Desjardin & Lumyong , (in Kerekes & Desjardin 2009: 120)), is also similar to C. minima in having small basidiocarps, a convex pileus with a brown center, cheilocystidia with apical appendages, the pileipellis hairs not turning green in KOH and the stipitipellis hyphae turning green in KOH. However, C. dipterocarpi has adnate to adnexed lamellae, a longer stipe (up to 50 mm long), the occasional presence of rhizomorphs, inamyloid lamellar trama, a hymenium devoid of pleurocystidia and the pileipellis hyphae with reddish brown encrustations ( Kerekes & Desjardin 2009). A pairwise comparison of the nrITS sequences of various GenBank accessions of C. dipterocarpi (FJ167656, FJ167651, FJ167655, FJ167648, FJ167653, FJ167652, FJ167650, FJ167654, FJ167649) with that of C. minima showed only less than 91% sequence similarity.

Crinipellis minima is also similar to C. pseudostipitaria var. pseudostipitaria Singer (1942: 470) , documented from the neotropics ( Singer 1976), in having a pileus with a depressed center, subclose lamellae, basidiospores of almost similar size and shape, presence of cheilocystidia with apical appendages and the pileipellis hairs with scattered septa. However, C. pseudostipitaria var. pseudostipitaria differs from C. minima in having a larger (up to 13 mm broad), fibrillose-woolly pileus in almost uniform color, longer and broader stipe (9–30 × 0.3–2 mm), a hymenium devoid of pleurocystidia and inamyloid lamellar trama.

A BLASTn search using the nrITS sequence (626 bp) of C. minima showed Crinipellis nigricaulis var. macrospora Antonín, Ryoo & H.D. Shin (2009: 431) (FJ573197) as the closest taxon with 89.92% similarity. While using nrLSU (896 bp) sequence, C. nigricaulis Har. Takah. (2000: 178) (MK277894: 99.44%) resulted as the closest hit. Similar to C. minima , C. nigricaulis has narrow lamellae up to 1 mm broad, the presence of cheilocystidia with apical appendages and a dextrinoid stipe trama. But C. nigricaulis can be distinguished from C. minima in having a longer stipe (50 mm long) with rhizomorphs, the absence of pleurocystidia, and longer pileipellis hairs (up to 1500 µm long) with numerous secondary septa forming ladder-structure ( Takahashi 2000). Crinipellis nigricaulis var. macrospora also has a longer (up to 200 mm long) stipe and a hymenium devoid of pleurocystidia ( Antonín et al. 2014).

Figures

FIGURE 2. A–L: Crinipellis minima (SA324 (CALI), holotype). A. Basidiocarps; B–D. Basidiospores; E. Basidium; F–G, J. Pleurocystidia; H–I. Cheilocystidia; K. Pileipellis; L. Stipitipellis. Scale bars:A = 5 mm; B–J = 10 µm; K = 20 µm; L = 50 µm.