Hohenbuehelia lageniformis Phonemany & Raspe, 2023

Phonemany, Monthien, Vadthanarat, Santhiti, Raghoonundon, Bhavesh, Thongklang, Naritsada & Raspe, Olivier, 2023, Additions to Hohenbuehelia (Basidiomycota, Pleurotaceae): two new species and notes on H. tristis from northern Thailand, MycoKeys 99, pp. 109-130 : 109

Hohenbuehelia lageniformis Phonemany & Raspe sp. nov.

Figs 4 , 5

Diagnosis.

This species is distinguished from other Hohenbuehelia species by having velutinous pileus with whitish hairs near the point of attachment, and at the margin, elsewhere pale greyish-yellow, and with only sparse white hairs, pale brown to light brown and mucilaginous context, subglobose to ellipsoid basidiospores, lageniform cheilocystidia, an ixotrichoderm pileipellis, and the absence of pileoleptocystidia.

Holotype.

Thailand, Chiang Mai Province, Mae On District, Huai Kaew Subdistrict, Pok Village, 29 June 2019, Monthien Phonemany (MFLU22-0010).

Etymology.

" lageniformis " refers to the lageniform shape of cheilocystidia.

Description.

Pileus 25-30 × 15-25 mm, spathuliform when young, rounded flabelliform to sub-rounded flabelliform when mature, light yellow (4A4), pale orange to orange white (5A2-5A3), greyish-orange (5B4) becoming darker with age, sometimes sessile or with laterally attached stipe; surface moist, shiny, velutinous with whitish (1A1) hairs near the point of attachment, elsewhere light yellow to pale greyish-yellow (4A4-4B4); margin discolorous from pileus, velutinous with whitish hairs as observed under the lens, incurved even when mature, entire or sometimes undulate when old. Lamellae 1-2 mm wide, decurrent, white to pale orange (5A1-5A2) becoming slightly dark in age, close to moderately crowded, in 2-3 tiers. Stipe absent or sometimes with pseudostipe 0.5-1 mm long when young and disappearing when mature. Context consisting of two layers: 1) non-gelatinous layer, 1 mm thick, fleshy, white (1A1); 2) gelatinous layer, 1-2 mm thick, soft, sticky, brownish-orange to light brown (5C5-5D5). Odour mild. Taste none. Spore print white.

Basidiospores [150/3/3] (6.9-)7-8.8-10(-10.5) × (5.5-)6-7.0-8(-8.3) µm, Q = (0.99-)1.11-1.26-1.49(-1.53) subglobose to ellipsoid in front view, ellipsoid to phaseoliform in side view, smooth, thin-walled, inamyloid. Basidia (24.3-)24-31.9-53(-58.2) × (5.4-)5.5-9.4-14(-14.6) µm, clavate, with (2)-4 sterigmata, 4-8 µm long, hyaline, smooth, thin-walled. Cheilocystidia (17.6-)18-21.9-26.5(-26.9) × (3.2-)3-5.0-9(-8.9) µm, lageniform with an inflated base with a thin, rostrate apex, hyaline, thin-walled. Pleurocystidia (31-)31-50.3-70(-71) × (9.7-)10-15.3-20(-20.3) µm, metuloidal, setiform, narrowly fusiform to fusiform, encrusted with crystals, brownish or yellowish in water, colourless, but still encrusted with crystals in KOH. Hymenophoral trama subregular, hyphae 2-4 µm wide. Pileipellis an intricate trichoderm with cylindrical terminal elements 41-122 × 2-5 µm. Pileoleptocystidia absent. Pileus trama consisting of two layers: 1) upper layer gelatinous, composed horizontally arranged, smooth, colourless, encrusted hyphae, 1-4 µm wide; 2) non-gelatinous layer, composed interwoven, smooth with hyaline hyphae, 2-5 µm wide. Clamp connections present in pileipellis, pileus trama and hymenophoral trama.

Habitat and distribution.

Solitary, gregarious to imbricate, on decaying branches in a tropical forests in northern Thailand.

Additional specimens examined.

Thailand. Chiang Rai Province, Muang Chiang Rai District, Mae Yao Subdistrict, Huai Mae Sai Village , 10 July 2019, Monthien Phonemany (MFLU22-0011); ibid., 10 July 2019, Monthien Phonemany (MFLU22-0012); ibid., 10 July 2019, Monthien Phonemany (MFLU22-0013) ; Pa Daed District, Pa Ngae Village , 7 September 2019, Monthien Phonemany (MFLU22-0014) .

Notes.

Hohenbuehelia lageniformis is characterised by velutinous pileus with whitish hairs near the point of attachment and at the margin, elsewhere pale greyish-yellow and with only sparse white hairs, subglobose to ellipsoid basidiospores, and the absence of pileoleptocystidia. Hohenbuehelia angustata , H. bonii , H. carlothornii , H. concentrica , H. flabelliformis , H. horrida , H. luteola , H. mellea Corner, and H. odorata have similar pileus colour, for example, pale orange to orange white, light yellow, yellowish-white, yellow-brown, honey-yellow or ochraceous brownish. However, those species have significant morphological differences. Hohenbuehelia angustata differs from H. lageniformis by having a smooth pileus surface, serrate margin, smaller basidiospores (3.5-5 × 2.5-3.5 µm), cutis pileipellis ( Silva-Filho and Cortez 2017). Hohenbuehelia bonii differs by having a smooth pileus surface and larger pleurocystidia (56-103 × 11-19 µm) ( Ainsworth et al. 2016). Hohenbuehelia carlothornii differs by having finely white-tomentose pileus, smaller basidiospores (7-8.2 × 3.1-3.7 µm), smaller basidia (19-24 × 5.2-6.8 µm), smaller cheilocystidia (13-17 × 4.9-9.4 µm), and larger pleurocystidia (55-63 × 14-18 µm) ( Consiglio et al. 2018b). Hohenbuehelia concentrica has larger basidiomata (80 mm wide), ovoid basidiospores (8-8.5 × 6-6.7 µm), and no cheilocystidia ( Corner 1994). Hohenbuehelia horrida has pale grey to greyish-brown lamellae, larger basidiomata (70 mm wide), smaller basidiospores (5-6 × 3-4 µm), smaller basidia (18-25 × 3-4 µm), and larger pleurocystidia (140 × 12.5 µm) ( Corner 1994). Hohenbuehelia luteola differs by smaller basidiospores (8-9 × 4.5-5 μm), and smaller pleurocystidia (45-50 × 15-20 µm) ( Stevenson 1964). Hohenbuehelia mellea has smaller basidiospores (5-6.5 × 2-3.5 µm), larger cheilocystidia (30-50 × 8-18 µm), and larger pleurocystidia (50-160 × 12-20 µm) ( Corner 1994). Hohenbuehelia flabelliformis has thinner gelatinous layer (0.5 mm), smaller basidiospores (6-8 × 4-5 µm), smaller pleurocystidia (34-54 × 8.5-14 µm), and no cheilocystidia. Hohenbuehelia odorata differs by having smaller basidiospores (5.2-7.6 × 4.8-6.4 µm), smaller cheilocystidia (15-23.5 × 3-7 µm), smaller pleurocystidia (28.5-49 × 10-14.5 µm), and presence of cylindrical to flexuous pileoleptocystidia ( Bijeesh et al. 2019).

In the phylogenic tree, the most closely-related species to H. lageniformis was H. odorata (voucher TBGT17443). However, the genetic distance between the ITS sequence of H. lageniformis and H. odorata was 4.62% (27/584), which supports the distinction of the two species. Moreover, these two species also show morphological differences (see above).

Figures

Figure 4. Basidiomata of Hohenbuehelia lageniformis on the substrate and detailed photographs in the lab a-c MFLU 22 - 0010 d MFLU 22 - 0012 e, f MFLU 22 - 0014. Scale bars: 1 cm (a-e); 2 cm (f).

Figure 5. Micromorphology of Hohenbuehelia lageniformis (MFLU 22 - 0010, MFLU 22 - 0012, MFLU 22 - 00104) a basidiospores b basidia c pleurocystidia d cheilocystidia e pileipellis. Scale bars: 5 µm (a); 20 µm (b, c); 10 µm (d); 50 µm (e).