Clitopilus chichawatniensis Fatima, Usman & Khalid, Phytotaxa 567(3): 261 (2022)
Index Fungorum number: IF 844802; MycoBank number: MB 844802; Facesoffungi number: FoF 15273; Figs. 1, 2, 3
Basidiomata clitocyboid to pleurotoid. Pileus 52–68 mm diam., surface white (1A1) to yellowish white (1A2), glabrous, margin non striate; context 1–2 mm thick at center, gradually thinner towards margin, white (1A1). Lamellae ca. 2 mm broad, decurrent, ventricose, yellowish white (1A2), concolorous, crowded with 2–3 series of lamellulae. Stipe 25–32 × 12–17 mm, gradually broader towards base, white (1A1) to yellowish white (1A2), unchanging on bruising; context white; base with well-developed mycelia. Taste not recorded. Odor unpleasant. Spore-print pinkish.
Basidiospores (6.4–)6.6–7.3–7.9(–8.4) × (4.8–)5.2–5.7–6.3(–6.4) µm, Q = 1.1–1.3–1.4, ovoid to broadly ellipsoid, apically angular, almost 3 to 5 ridges present, hyaline, thin-walled. Basidia 26–31 × 7.5–10.5 µm, broadly clavate, hyaline, thin-walled; 4-spored. Basidioles 23–33.5 × 5.5–9.0 µm, clavate, hyaline, thin-walled. Pleurocystidia and Cheilocystidia absent. Pileipellis a cutis, composed of irregular, agglutinated, smooth, cylindrical, branched, thin-walled hyphae measuring 23–26 × 2.5–5.5 µm. Stipitipellis hyphae 2.5–4.1 µm broad, regular, hyaline, thin-walled. Clamp-connections absent in all tissues.
Material examined – INDIA, West Bengal, Paschim Bardhaman district, Durgapur, Malandighi, 23°33’51.2″N 87°24’11.2″E, 92.9 m asl., 11 Sept 2022, A.K. Dutta & P. Chattopadhyay, GUBH 20327.
GenBank – GUBH 20327: OR880555 (ITS).
Notes – The species Clitopilus chichawatniensis was first discovered in Pakistan and herein reported for the first time from India. Morphologically, the Indian collection nicely match with the type specimen description (Fatima et al. 2022). In the phylogenetic tree (Fig. 3), the newly generated sequence of the Indian collection cluster together with the type specimen sequence (GenBank ON980767) with full support values (MLBS = 100%, PP = 1.00), suggesting them to be conspecific. However, morphologically, the present collection consists of well-developed, clavate pleurocystidia measuring 23–33.5 × 8.0–9.0 µm, which was reported to be absent in the type specimen. Otherwise, all the remaining morphological features of the Indian collection nicely match with the type specimen description (Fatima et al. 2022). Phylogenetically, C. albidus appears to be related to C. chichawatniensis but differs in having smaller pileus (7–34 mm) colored white and much smaller (mean of 4.5 × 3.6 µm vs. 7.3 × 5.7 µm in C. chichawatniensis), subglobose to ellipsoid basidiospores (Raj and Manimohan 2018).
Figure 1 – Basidiomata of Clitopilus chichawatniensis (GUBH 20327). a Pileus surface morphology. b Lamellae attachment to the stipe. Scale bar = 10 mm.
Figure 2 – Microscopic features of Clitopilus chichawatniensis (GUBH 20327). a–b SEM microphotographs of basidiospores. c Basidia. d Basidioles. e Stipitipellis hyphae. Scale bars: a = 1 µm, b = 300 nm, c–d = 10 µm, e = 5 µm.
Figure 3 – The Maximum Likelihood tree (-lnL = 3663.063549) was generated using a GTR + I + G model of nucleotide evolution based on the nrDNA ITS sequence data. ML bootstrap support (MLBS) = 50% (on the left of ‘/’) and Bayesian posterior probability support values (PP) = 0.50 (on the right of ‘/’) are indicated above or below the nodes. The scale bar represents the expected changes per site. The newly generated sequences for the present study are placed in red font. The GenBank accession number along with the country of origin are indicated after each taxon name in the tree.