Tylopilus hayatae Rodríguez-Ramírez & Luna-Vega, 2020

Rodríguez-Ramírez, Ernesto Chanes, Martínez-González, César Ramiro, González-Ávila, Patricia Astrid & Luna-Vega, Isolda, 2020, Tylopilus hayatae, a new endemic bolete species in relict Mexican beech forest, Phytotaxa 441 (1), pp. 35-46 : 37-39

Tylopilus hayatae Rodríguez-Ramírez & Luna-Vega , sp. nov. ( Fig. 2A–D )

Index Fungorum:—IF number 556969.

Etymology:—‘ hayatae’ is derived from Latin and refers to the common name of the Mexican beech ‘haya’.

Holotype:— Mexico. Hidalgo state, Zacualtipán de Ángeles municipality, La Mojonera locality, 1 August 2009, in soil under Fagus grandifolia subsp. mexicana . Rodríguez-Ramírez 180 ( M – UAEH 752 ).

Diagnosis:—This species is distinguished from others in the genus Tylopilus by molecular sequences obtained from tef 1-α, rpb1 and rpb2, and its velvety uniformly black pileal surface, reticulate to faintly longitudinally striate stipe with bulbose base, and yellowy white to light brownish basidiospores.

Description: —Basidiome small to medium. Pileus 90–110 mm diam, plano-convex to broadly convex with incurved margin when young, expanding to sub-applante then applanate, velvety, non-hygrophanous, smooth; uniformly black, fading with age and sun exposure, developing grayish tints (1B1) especially towards the margin. Context pileus 10–15 mm thick over the stipe, white (1A1), unchanging in color, fleshy. Tubes 6–7 mm deep, depressed around stipe, light gray (4B3) when young, unchanging in color when older or when bruised. Pores 0.5–1 mm diam, mostly round, slightly radially elongated when mature at stipe, smaller near pileus margin, pale gray, concolorous with tubes. Stipe 60–80 × 10–17 mm, central, clavate to sub-clavate, with fine black reticulation to black faintly longitudinally striate, equal and curved or with bulbose base, yellowy white to light brown (5A3), changing to yellowy (1A8) when bruised, with white (1A1), basal mycelium. Taste not much and Odor mild, fruity at times with hints of cherry. Context light brown (4A2), changing to light yellow (3A4). Macrochemical reactions see Table 3.

Basidiospores (8.5–)10–15.5 × (3.8–)4–5 µm, Q= (4.9–)5–5.4(–5.5), Q m = 5.2 ± 0.23, sub-fusiform to fusiform, cylindrical to somewhat oblong, smooth, thin-walled (<1 µm), guttulate, yellowish to brownish in 10% KOH ( Figs. 2E , 3A ). Basidia (18–)20–40 × 7.5–10(–12) µm (n = 30), clavate to sub-clavate, clamped at base, thin-walled, hyaline to yellowish in 10% KOH ( Fig. 3B ) tetrasporic, sterigmata 2–4 µm long. Cheilocystidia (18–)20–27 × 8–11(–13) µm (n = 40), abundant, ventricose, sub-fusiform to sub-clavate, thin-walled, hyaline to yellowish in 10% KOH. Chrysocystidia 18–26(–30) × 7.5–10(–12) µm (n = 40), similar in shape to cheilocystidia, containing yellowish pigments in 10% KOH. Pseudocystidia not seen. Pileipellis a trichodermium, of thin˗ to slightly thick-walled, generative vertical hyphae, subcylindrical to cylindrical, branched in form of an ‘H’, colorless to pale yellowish in 10% KOH, clamp connections present, clavate or nearly fusoid ( Fig. 3E ), 4–6 µm diam. Pileus trama of slightly thick-walled vertical hyphae, 4˗6 µm diam, hyaline in 10% KOH. Stipitipellis a hymeniderm composed of thin-walled (<1 µm) emerging hyphae with clavate or sub-fusiform terminal cells (4–8 µm diam), hyaline in 10% KOH. Stipe trama composed of longitudinally arranged, parallel hyphae (2–)3–7(–7.5) µm diam, cylindrical, thin-walled, hyaline in 10% KOH. Lateral stipe stratum undifferentiated from the stipe trama (‘boletoid type’), at the stipe apex a thick layer consisting of divergent, loosely intermingled and branched hyphae remaining separate and embedded in a mucilaginous substance. Clamp connections present on hyphae in all tissues.

Habit, habitat and distribution:—scattered under rocky slopes areas (43.8° slope) in Mexican beech ( Fagus grandifolia subsp. mexicana ), solitary to gregarious in vitric and humic andosol soil, pH values of 4 to 6, with light sandy clay loam texture, eastern Hidalgo State, Mexico (20° 37’ 52’’N 96° 36’ 34’’ W, 1958 m asl).

Additional specimens examined:— Mexico, Hidalgo State, Zacualtipán de Ángeles municipality, La Mojonera locality, 20° 37’ 52’’N 96° 36’ 34’’ W, 1958 m asl, 28 July 2018, Rodríguez-Ramírez 2013 (paratype FCME –2013) ; Mexico. Hidalgo: Zacualtipán de Ángeles municipality, La Mojonera locality, 6 August 2019, Rodríguez-Ramírez 2017 (paratype FCME –2017) .

Figures

FIGURE 2. Tylopilus hayatae Rodríguez-Ramírez & Luna-Vega: A and B basidiome Rodríguez-Ramírez 185–186; C Rodríguez-Ramírez 180 (holotype); D stipe reticulum; E basidiospore. Scale bars: (A) 20 mm, (B–C) 10 mm, (D) 100 mm; (E) 4 µm. Photos: A–D Ernesto C Rodríguez-Ramírez; E César R. Martínez-González.

FIGURE 3. Microscopic features of Tylopilus hayatae Rodríguez-Ramírez & Luna-Vega (Rodríguez-Ramírez 180, holotype). A basidiospores; B basidia; C cheilocystidia; D chrysocystidia; E pileipellis. Bars: (A) 4 mm, (B–E) 0.09 µm. Drawings: EC Rodríguez- Ramírez.