Candolleomyces gregalis P.K. Nayana & C.K. Pradeep, 2025

Nayana, P. K. & Pradeep, C. K., 2025, New species and new geographic record of Candolleomyces (Psathyrellaceae, Agaricales) from India, Phytotaxa 691 (1), pp. 34-48 : 40-46

Candolleomyces gregalis P.K. Nayana & C.K. Pradeep sp. nov. ( Figs. 2 , 3 )

MycoBank: MB856061.

Diagnosis:—Differs from C. niveofloccosus in its smaller pileus (10–23 mm), brown pileal veil, small basidiospores (6.4–7.2 × 4.4–5.2 µm), slightly smaller cheilocystidia (16.3–26.5 × 7.1–14.1 µm), gregarious habit, and molecularly with 12 base pair differences (nrITS).

Holotype:— INDIA, Kerala State: Thrissur District, Chimmini Wildlife Sanctuary , 10.43ᵒN, 76.46ᵒE, elev. 75 m, 16 July 2023, Nayana TBGT ( M)19327!. GenBank: PQ415499 (nrITS); PQ415501 (nLSU).

Etymology:— gregalis , refers to the gregarious habit of the new species.

Description:—Basidiomata small, thin, fragile. Pileus 10–23 mm diam., conical, convex or campanulate with or without a small obtuse umbo at centre; surface brown to dark brown (6E4/6E5–6F6/7F4/7F5), hygrophanous to orange gray (6B2) or grayish orange (5B3) with brown evanescent floccose velar squamules scattered throughout, pellucid striate, dry; margin straight, entire to incised. Lamellae adnexed, grayish orange to dark brown (5A2/6D4/6E4/6E5/ 6F4–6F6), up to 2.5 mm wide, close with lamellulae of different lengths; edge concolorous to the sides, fimbriate. Stipe 30–62 × 0.5–2.0 mm, central, cylindric, straight or slightly curved, hollow, brittle; surface white or grayish yellow (4B3), pruinose at the apex, smooth and glabrous; base with white strigose hairs. White mycelial mat present. Context concolorous to the pileus, 1 mm wide, soft. Odor nil; taste not recorded

Basidiospores 6.4–7.2 × 4.4–5.2 µm (avL= 6.8 µm, avW= 4.8 µm), Q= 1.2–1.5 (Qm= 1.4), broadly ellipsoid to ellipsoid, brownish orange in water, grayish brown in 3% aqueous KOH, thick-walled, smooth, with an indistinct germ pore and minute hilar appendix. Basidia 14.2–18.8 × 6.6–7.3 µm, clavate, 4-spored, thin-walled, hyaline. Lamella edge sterile with crowded cheilocystidia along with paracystidia. Cheilocystidia 16.3–26.5 × 7.1–14.1 µm, utriform, cylindrical, obovoid or ellipsoid, thin- or slightly thick-walled, hyaline. Paracystidia moderately abundant, 9.4–17.2 × 7.3–12.8 µm, globose to subglobose, thin-walled, hyaline. Pleurocystidia absent. Hymenophoral trama regular, hyphae 2.6–7.8 µm wide, branched, thin-walled, hyaline to very pale brown in KOH. Pileal trama composed of thin-walled, encrusted, brown, inflated, 2.2–44.4 µm wide hyphae. Pileipellis an epithelium, composed of globose to subglobose elements, 31–59.9 × 29.2–43.6 µm, thin-walled, hyaline. Stipitipellis a cutis, made up of thin-walled, hyaline, 2.2–8.8 µm broad encrusted hyphae. Stipe apex with caulocystidia along with paracystidia. Caulocystidia abundant, 23.1–44.6 × 6.4–15 µm, lageniform or utriform with an obtuse or subcapitate apex, slightly thick-walled, hyaline. Paracystidia rare, 13.7–18.9 × 11.4–12.9 µm, globose to subglobose, thin-walled, hyaline. Velar remnants composed of 16.9–46.2 µm wide, branched, encrusted, slightly thick-walled hyphae with brown contents. Clamp connections present in all parts.

Ecology and distribution:—Gregarious on dead angiosperm wood, branches, or twigs. Known only from the type locality in India.

Additional specimens examined:— India, Kerala state, Thrissur district, Chimmini Wildlife Sanctuary : 10.43ᵒN, 76.46ᵒE, elev. 75 m, 16 July 2023, Nayana TBGT ( M)19332 (nrITS: PQ415502; nrLSU PQ415504 ) ; ibid., 16 July 2023, Nayana TBGT ( M)19334 ; 16 July 2023, Nayana TBGT ( M)19335 ; Kollam District, Thenmala, Shendurney Wildlife Sanctuary : 77.16ᵒN, 9.14ᵒE, elev. 1169 m, 20 June 2023, Nayana TBGT ( M)19241 ; ibid., 20 June 2023, Nayana TBGT ( M)19242 ; 20 June 2023, Nayana TBGT ( M)19243 .

Notes:— Candolleomyces gregalis is identified by its small basidiomata, brown to dark brown pileus containing brownish evanescent floccose velar squamules, brownish orange ellipsoid basidiospores with an indistinct germ pore, sterile lamella edge with numerous polymorphic cheilocystidia, lageniform to utriform caulocystidia, hyphal velar remnants with brown contents and lignicolous habitat.

In molecular phylogenetic analysis C.gregalis shows close similarity with an unidentified species of Candolleomyces from China and C. niveofloccosus from India ( Nayana & Pradeep 2023b). However, C. niveofloccosus differs in its larger pileus (20–42 mm), larger basidiospores (7.2–8.0 × 4.0–4.8 µm), larger cheilocystidia (20.0–32.5 × 9.0–15 µm), and presence of white pileal veil. Moreover, the pairwise comparison of the nrITS sequences of C. gregalis with C. niveofloccosus resulted in 12 base pair differences ( Table 2). The Chinese species (FCATAS3434) may be conspecific with the current Indian species ( Fig. 1 ), however, lack of morphological details of the Chinese species warrant such a conclusion. Candolleomyces subcacao , another closely related species documented from China can be differentiated by its larger pileus (11–35 mm), slightly larger basidiospores (6.8–8.0 × 3.9–4.9 µm) with a distinct germ pore, and slightly larger (22–36 × 9.8–14 µm) cheilocystidia (Bau & Yan 2021) and molecularly by 11 base pairs (Table-2). Candolleomyces cacao exhibits notable similarities in macromorphology with C. gregalis . However, the former is distinct by its slightly smaller pileus (5–15 mm), smaller basidiospores (5.7–6.8 × 3.5–4.5 µm) without a germ pore, slightly smaller ventricose to lageniform cheilocystidia (16.5–20 × 8.5–9.0 µm), absence of a veil ( Desjardin & Perry 2016) and shows 12 base pair differences in a pairwise comparison of nrITS sequences.

Some of the other related Asian species include: Candolleomyces parvipileus A. Javaid & Naseer (2024: 11) , C. campanulatus A. Izhar, Z. Khan & Khalid (2023: 40) , C. amygdaliformis Haqnawas, Niazi, I. Ahmad & Khalid (2024: 281) , and C. asiaticus Asif, A. Izhar, Niazi & Khalid (2022: 180) . The presence of white pileal veil, larger basidiospores (4.7–9.3 × 3.7–5.7 µm) without a germ pore, larger cheilocystidia (18–38 × 10–18 µm) and caespitose habit on soil differentiates C. parvipileus from C. gregalis (Haqnawas et al. 2024) . Candolleomyces campanulatus can be distinguished by its larger basidiospores (8.0–11 × 4.5–5.5 µm) with a distinct germ pore, larger clavate to utriform cheilocystidia (22–50 × 11–19 µm), and white pileal veil ( Izhar et al. 2023). Larger basidiospores (7.4–9.5 × 4.4–5.6 µm) with distinct germ pore, larger cheilocystidia (23–40 × 8.1–11 µm) and terrestrial habitat makes C. amygdaliformis distinct from C. gregalis ( Ahmad et al. 2024) . Candolleomyces asiaticus , a recently described species from Pakistan ( Asif et al. 2022) can be separated by its larger pileus (30–63 mm), white pileal veil, significantly larger basidiospores (7.2–7.6 × 4.5–6.0 µm) and larger cheilocystidia (21–38 × 9.6–16 µm).

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Candolleomyces typhae (Kalchbr.) D. Wächt. & A. Melzer, Mycol. Progr. 19(11): 1234 (2020) ( Figs. 4 , 5 ) ≡ Agaricus typhae Kalchbr., Mathem. Természettud. Közlem. 2: 160 (1863)

≡ Psathyra typhae (Kalchbr.) Sacc., Syll. fung. (Abellini) 5: 1067 (1887)

≡ Psathyrella typhae var. iridis Boud., Bull. Soc. mycol. Fr. 13(1):13 (1897)

≡ Pilosace typhae (Kalchbr.) Kuntze, Revis. gen. pl. (Leipzig) 3(3): 504 (1898)

≡ Pratella typhae (Kalchbr.) Henn. , in Engler & Prantl, Nat. Pflanzenfam. (Leipzig) 1(1**): 235 (1898)

≡ Drosophila typhae (Kalchbr.) Romagn., Bull. mens. Soc. linn. Soc. Bot. Lyon 13: 51 (1944)

≡ Psathyrella typhae (Kalchbr.) A. Pearson & Dennis, Trans. Br. mycol. Soc. 31(3-4): 185 (1948)

≡ Psathyrella typhae f. acori J. Veselský, Ĉas. Slezsk. Mus. Opavě, Ser. A 14: 56 (1965)

≡ Psathyrella typhae var. bispora Kits van Wav., Persoonia, Suppl. 2: 282 (1985)

Description:—Basidiomata small to medium, thin. Pileus 8–24 mm diam., convex, plano-convex to applanate with a small obtuse umbo at centre; surface whitish or yellowish white (4A2/3A2) with brownish orange (5C3/5C4) disc, with very pale brown, evanescent fibrillose to floccose velar squamules dense at centre, scattered towards the margin, subrugulose, dry; margin straight, incised. Lamellae adnexed, brownish orange to grayish brown (5C3-5D3/6D3), up to 2.5 mm wide, moderately crowded with lamellulae of 3 lengths; edge white, fimbriate. Stipe 20–52 × 1.0–3.0 mm, central, cylindric, tapering up from a broad base, curved, hollow, brittle; surface white, pruinose at the apex, densely covered with white fibrils or floccose velar squamules or with a denser fibrillose zone towards the base. White mycelial mat present. Context concolorous to the pileus, 0.5 mm thick, soft. Odor nil. Spore print dark brown (6F6).

Basidiospores 14–16 × 7.2–8.8 µm (avL= 15.2 µm, avW= 8 µm), Q= 1.7–2.1 (Qm= 1.9), elongate to cylindrical, yellowish gray in water, hyaline in 3% aqueous KOH, thick-walled, smooth, without a germ pore. Basidia 21.0–23.7 × 10.9–12.9 µm, clavate, 1- to 2-spored, thin-walled, hyaline. Lamella edge sterile with crowded cheilocystidia along with scattered paracystidia. Cheilocystidia 21–51 × 7.5–15.4 µm, polymorphic, utriform, lageniform, cylindrical, fusiform, thin or slightly thick-walled, hyaline with obtuse or subcapitate apex. Paracystidia moderately abundant, 11–25 × 7.5–14.5 µm, globose, subglobose or spheropedunculate, thin-walled, hyaline. Pleurocystidia absent. Hymenophoral trama regular, hyphae 2.0–6.8 µm wide, branched, thin-walled, hyaline. Pileal trama composed of thin-walled, brown, branched, encrusted, 4–16 µm wide hyphae constricted at septa. Pileipellis an epithelium, made up of subglobose or spheropedunculate elements, 30.6–45.2 × 16.7–27.7 µm, thin-walled, hyaline or with pale brown contents. Stipitipellis a cutis, made up of thin-walled, hyaline, 3.2–17.5 µm broad hyphae. Stipe apex with caulocystidia along with paracystidia. Caulocystidia crowded or scattered, moderately abundant, 27.9–70.6 × 7.3–9.0 µm, utriform, lageniform, cylindrical or clavate, slightly thick-walled and hyaline. Paracystidia scattered, moderately abundant, 16–20 × 8–11 µm, globose to subglobose, slightly thick-walled, hyaline. Veil composed of 2.4–11.8 µm wide, branched, sometimes encrusted, thin-walled, hyaline or very pale brown hyphae. Clamp connections present all parts.

Ecology and distribution —Scattered, in groups or caespitose on decaying banana stem or on soil containing banana plant debris. Known from France, Czechoslovakia, USA, Switzerland, Czech, and Turkey.

Additional specimens examined:— India, Kerala State, Kasaragod District, Badiadka , 12.5ᵒN, 75.0ᵒE, elev. 19 m, 25 September 2023, Nayana TBGT ( M)19427 (nrITS PQ415503 ) ; Kollam district, Achankovil , 10ᵒN, 76.28ᵒE, elev. 177 m: 12 January 2024, Nayana TBGT ( M)19494 (nrITS PQ415500 ) ; ibid, 12 January 2024, Nayana TBGT ( M)19500 .

Notes:— Candolleomyces typhae was reported from many places by different workers viz., France ( Boudier 1897), Czechoslovakia ( Kotlaba 1952), USA ( Smith 1972), Switzerland ( Breitenbach & Kränzlin 1995), Czech ( Vašutová 2006), and Turkey ( Ileri et al. 2019). Small to medium basidiomata, pileus with very pale brown fibrillose to floccose velar squamules, larger pale basidiospores without a germ pore, sterile lamella edge with larger, abundant, polymorphic cheilocystidia, polymorphic caulocystidia characterize C. typhae . It is usually found on dead leaves and culms of Typha ( Smith 1972; Kits van Waveren 1985) however, was also found on leaves of Iris , Carex , and Sparganium ( Boudier 1897) .

BLASTn search using the nrITS sequence of the Indian collection [TBGT(M)19494 (PQ 415500); TBGT(M)19427 (PQ415503)] clusters with C. typhae from Sri Lanka and China with significant BS and PP (100%/1.0) values proving conspecificity ( Fig. 1 ). Except for the slightly bigger basidiospores, the existence of exclusive 1–2-spored basidia, and habitat on banana stems and leaves, the morphology of the current sample conforms well with the earlier descriptions. Slightly larger basidiospores,1–2-spored basidia were also reported by Kits van Waveren (1985), who treated it as a variety viz ., Psathyrella typhae var. bispora , and currently thought to be a synonym of C. typhae ( Wächter & Melzer 2020) .

Candolleomyces typhae has not been previously reported from India and hence represents a new geographical record.

Figures

FIGURE 1. ML tree generated from combined dataset (nrITS and nLSU). Bootstrap values and Bayesian posterior probabilities ˃50%/0.8 (BS/PP) are indicated above/below branches. Species from the current study are indicated in bold.

FIGURE 2. Candolleomyces gregalis (TBGT(M)19327, holotype). A–D. Habit in situ; E, F. Lower view of basidiomata showing lamellae. Scale bars = 10 mm. Photos: P.K. Nayana.

FIGURE 3. Candolleomyces gregalis (TBGT(M)19327, holotype). A. Basidia; B. Basidiospores; C. Lamella edge with cheilocystidia; D. Scattered cheilocystidia; E. Pileipellis; F. Caulocystidia; G. Veil elements. Scale bars: A, B = 10 µm; C, D, F, G = 20 µm; G = 50 µm; Photos by: P.K. Nayana.

FIGURE 4. Candolleomyces typhae. A. Habit in situ; B. Lamella view; C, D. Mono and bisporic basidia; E. Basidiospores. Scale bar: A, B = 10 mm; C–E = 10 µm. Photos by: P.K. Nayana.

FIGURE 5. Candolleomyces typhae. A. Lamella edge with cheilocystidia; B. Scattered cheilocystidia; C. Pileipellis; D, E. Caulocystidia; F. Veil elements. Scale bars: A = 20 µm; B–F= 50 µm; Photos by: P.K. Nayana.