Collybiopsis indocta (Corner) R.H. Petersen, Mycotaxon, 2021

Kumla, Wiphawanee Phonrob Jaturong, Suwannarach, Nakarin, Khuna, Surapong, Nutaratat, Pumin, Wannathes, Nopparat & Lumyong, Saisamorn, 2024, Five new records of Collybiopsis (Agaricales, Omphalotaceae) in Thailand: a significant addition to the species diversity and global distribution of the genus, Phytotaxa 650 (3), pp. 213-235 : 226-227

Collybiopsis indocta (Corner) R.H. Petersen, Mycotaxon 136(2): 342 (2021) FIGURE 5

Index Fungorum number: IF556188

Pileus 13–40 mm diam., plano-convex to concave-infundibuliform, subumbilicate, striate, glabrous, margin translucent-striate, orange white to grayish orange (5–6A–B2–5) at center becoming creamy or orange white to white (5A1–2) at margin, hygrophanous turning creamy orange with moisture loss. Context thin (1 mm), white. Lamellar adnate, close to subdistant (20–28) with 2–4 series of lamellulae, white, narrow (2–3 mm). Stipe 29–67 × 2–4(8) mm, central, tap compressed, hollow to fistulose, squamulose at apex, fibrillose at base, orange white to grayish orange (5–6A–B2–5), the apex yellowish white (4A2), basal tomentum of matted hyphae.

Basidiospore [75/3/3] (6.5)7–9(9.5) × 3–5(5.5) µm [x̄ = 8.4 ± 0.63 × 3.68 ± 0.48 µm, Q = 1.7–2.8, Q m = 2.31 ± 0.25] elongate-ellipsoid, smooth, hyaline, inamyloid, thin-walled. Basidia 14–22 × 5–7 µm, clavate, with 4 sterigmata, thin walled. Cheilocystidia abundant, 28–36 × 7–12 µm, irregular in shape, lobe, smooth, hyaline, inamyloid, thin-walled. Pleurocystidia absent. Lamellar trama interwoven, hyphae 4–13 µm, cylindrical, smooth, hyaline, inamyloid, thin-walled. Pileipellis cutis of radially arranged hyphae 3–5 µm, cylindrical, yellowish brown, inamyloid, non-diverticulate, smooth to weakly incrusted. Pileocystidia 16–40 × 4–7 µm, cylindrical, hyaline, inamyloid, thin-walled. Pileus trama subregular, 5–12 µm, cylindrical, branched, smooth, inamyloid, thin-walled. Stipitipellis cutis, 3–8 µm, cylindrical, yellowish brown, smooth, thin-walled, non-incrusted. Stipe trama parallel, 3–6 µm, cylindrical, smooth, pale yellow, inamyloid. Caulocystidia abundant, 42–62 × 3–5 µm, cylindrical-flexuose, irregular in shape, sometimes occurring in short chains, clustered, smooth, hyaline, inamyloid thin walled. Clamp connections are present in all tissues.

Habitat and known distribution:—Fruiting gregarious to solitary on twigs and wood. Known from Indonesia (Java) ( Wilson et al. 2004), Singapore ( Corner 1996), and Thailand (This study).

Material examined:— THAILAND, Phatthalung Province, Khuan Khanun, sago palm ( Metroxylon sagu ) forest, 7°43´54´´N 99°59´46´´E, elevation 20.1 m, decaying wood and twigs, 24 October 2022, P. Nutaratat, J. Kumla, and N. Suwannarach, SDBR-TSU027.

Note:—The macroscopic and microscopic features of the Thai materials were similar to the descriptions by Corner (1996) and Wilson et al. (2004), but the basidiospores in the Thai materials (3–5.5 µm wide) were slightly wider than the descriptions of specimens (4–4.2 µm wide) by Corner (1996) and Wilson et al. (2004). The variability of the size of basidiospores may be influenced by the environment across a wide geographic range. Thai materials were found to belong to the C. indocta clade ( FIGURES 2 and 3 ). Morphologically, C. indocta is similar to C. menehune . However, C. menehune has darker pileus (buff-brown to brownish-yellow), and diverticulate terminal cells are present ( Desjardin et al. 1999). However, C. indocta formed a monophyletic clade and was separated from C. menehune ( FIGURES 2 and 3 ).

Figures

FIGURE 2. Phylogenetic tree derived from maximum likelihood analysis of 95 sequences of the combined ITS and nrLSU genes. Sequences of Rhodocollybia maculata TFB14382 and R. butyracea TFB13989 were used as outgroups. The numbers above the branches represent bootstrap percentages (left) and posterior probabilities (right). Bootstrap values ≥ 75% and posterior probabilities ≥ 0.90 are shown. The scale bar represents the expected number of nucleotide substitutions per site. Sequences of specimen vouchers obtained in this study are highlighted in red. Type species are shown in bold.

FIGURE 3. Phylogenetic tree derived from maximum likelihood analysis of 95 ITS gene sequences.Sequences of Rhodocollybia maculata TFB14382 and R. butyracea TFB13989 were used as outgroups. The numbers above the branches represent bootstrap percentages (left) and posterior probabilities (right). Bootstrap values ≥ 75% and posterior probabilities ≥ 0.90 are shown. The scale bar represents the expected number of nucleotide substitutions per site. Sequences of specimen vouchers obtained in this study are highlighted in red. Type species are shown in bold.

FIGURE 5. Collybiopsis indocta (SDBR-TSU027). A. Basidiomata; B. Basidiospores; C. Basidia; D. Cheilocystidia; E. Pileipellis; F. Caulocystidia. Scale bars:A = 10 mm, B–F = 10 µm.