Baorangia major

Baorangia major Raspé & Vadthanarat.

Index fungorum nuber: 824250 MycoBank number: MB824250; Facesoffungi number: FoF05722

Basidiomeslarge when mature. Pileus(7–)16–22(–23) cm diam., at first hemispherical to convex, becoming convex to plano-convex and sometimes slightly depressed at the centre, greyish red (11C–E5) to greyish ruby (12B–E5), more rarely greyish pink (around 10A3), paler in spots and in age; margin involute at first, later inflexed, slightly exceeding; concolorous or abruptly paler (yellowish white; 2A2); surface even, dry, dull, subtomentose; context 1.7–3.8 cm thick half-way to the margin, firm at first, soft in age, off-white to yellowish white (1A2), slightly marmorated above the hymenophore, blueing when bruised, sometimes only weakly, then slowly getting yellow (3A5–6) with time, as in worm wounds. Stipe central, terete, cylindrical to subclavate (4.8–)5.2–8.5(–15) × 1.5–3.3(–4.5) cm; surface finely and densely dotted, subceraceous, dull, with off-white to pale yellow basal tomentum; context solid, yellowish white (2A2) at the top, more intensely yellow towards the base, marmorated, often with dark red spots, especially in the lower half, quickly and intensely blueing when cut. Hymenophore tubulate, decurrent; tubes 2–5 mm long, not separable, yellow (2–3A7), sometimes stained red at places (old bruises) or when old, quickly and intensely blueing when bruised; pores 2–5 mm wide at mid-radius when mature, mostly angular, elongated and radially arranged near the stipe, yellow (2A8), quickly and intensely blueing when bruised, sometimes reddish when very old. Odour fungoid to slightly fruity. Taste mild, fungoid. Spore print olive-brown. Macrochemical reactions: KOH pale orange on pileus and stipe, paler on context, null or merely slightly orangish on hymenium; NH4OH null. Basidia 4-spored, (36–)36–42.2–55(–55) × (8.5–)8.5–9.3–11(–11) μm (n = 20), narrowly clavate, sometimes curved, hyaline, with sterigmata up to 5 μm long, without basal clamp connection. Basidiospores (6–)7.5–8.1–9(–10) × (4–)4–4.6–5(–5.5) μm Q = (1.44–)1.5–1.8–2.1(–2.4) [N = 5/5/265]. From the type (7.5–)8–8.6–9.5(–9.5) × (4–)4–4.5–5(–5) μm, Q = (1.6–)1.69–1.9–2.13(–2.13) [n = 55], ellipsoid to ovoid, thin-walled, smooth, yellowish to greenish hyaline in water, KOH or NH4OH, yellowish in Melzer’s reagent. Cheilocystidia thin-walled, hyaline, of two different shapes, the first clavate to broadly clavate, (21–)21–29.3–37(–37) × (11.5–)11.5–13.1–15(–15) μm, the second fusiform to broadly fusiform, (26–)26–38.9–57(–57) × (10–)10–13.3–15(–15) μm. Pleurocystidia infrequent, fusiform to narrowly fusiform with obtuse apex, (44–)44–54.4–70(–70) × (8–)8–9.5–12(–12) μm, thin-walled, hyaline. Hymenophoral trama divergent, 90–112 μm wide, composed of 4–10 μm wide, hyaline hyphae, with regular mediostratum 30–45 μm wide. Pileipellis a trichoderm to tangled trichoderm, 170–190 μm thick, made of moderately interwoven and somewhat anastomosing, thin-walled, hyaline hyphae; terminal cells cylindrical with rounded apex, 20–58 × 4–9 μm, mostly hyaline to slightly pale yellowish brown at places in KOH. Pileus context made of moderately interwoven, hyaline, thin-walled hyphae, 4–13 μm wide. Stipitipellis a hymeniderm, 62–88 μm thick, mostly composed of basidiole-like cells, 12–43 × 4–10 μm. Caulocystidia infrequent, of three shapes, the first clavate to broadly clavate, (13–)23.8(–31) × (10–)12.5(–15) μm, thin-walled, hyaline, the second fusiform to broadly fusiform, (21–)31.5(–45) × (9.5–)11.6(–15), thin-walled, hyaline, and the third cylindrical, slightly curved, mostly hyaline, at places slightly yellowish brown in KOH. Stipe context composed of parallel, 4–12 μm wide, hyaline and somewhat anastomosing hyphae. Clamp connections not seen in any tissue.

Material examined: THAILAND, Chiang Mai Province, Mae Taeng District, around Mushroom Research Center, N19°07.1’–E98°44.0’, elev.900 m, 2 July 2010, P. Sysouphanthong, OR070 (MFLU!, BR!); ibid., N19°07.2’–E98°43.9’, elev.915 m, 17 June 2011, O. Raspé & S.C. Karunarathna, OR197 (MFLU!, BR!); N19- 06.50–E98–4.50, elev.1075 m, 18 June 2011, O. Raspé & S.C. Karunarathna, OR209 (MFLU, holotype; BR, isotype); N19°06.6’–E98°44.5’, elev.1055 m, 7 June 2012, O. Raspé & K. Wisitrassameewong, OR404; N19°07.2’–E98°43.9’, elev.910 m, 29 July 2013, O. Raspé & B. Thongbai, OR657 (MFLU!, BR!); CHINA, Yunnan Province, Cangyuan County, Banhongxiang, along the road, N23° 18.6’–E99°05.3’, elev.1010 m, 10 July 2012, O. Raspé & R.L. Zhao OR486 (HMAS).

Habit and habitat: Mostly gregarious, sometimes fasciculate or solitary, on soil in forests dominated by Lithocarpus spp., Castanopsis spp., sometimes mixed with Dipterocarpus spp.

Distribution: Known from Chiang Mai Province, Thailand and Yunnan Province, China.

Notes: Baorangia major can easily be recognised in the field by its large basidiomes when mature, decurrent hymenophore with large, angular, radially arranged (at least near the stipe), and 1–3 times compound pores, red stipe that immediately and intensely turns blue when injured or merely touched. In their diagnosis of Baorangia, Wu et al. (2015) mentioned ‘‘context which stains pale blue slowly when cut’’. While this fits B. major pileus context, it does not fit its stipe context, which quickly and intensely stains blue when cut. Baorangia bicolor (Kuntze) G. Wu et al. and B. rufomaculata (see below) somewhat resembles B. major, but the latter can easily be distinguished by the large angular pores and intense blueing.

Fig. 1 Maximum likelihood tree inferred from three-gene dataset (ATP6, RPB2 and TEF1-a). Retiboletus griseus, R. fuscus, and Rhodactina rostratispora were used as the outgroup taxa. Sequences retrieved from GenBank were originally published in Halling et al. (2012), Wu et al. (2014, 2015, 2016), Zhao et al. (2014a, b), Raspé et al. (2016), and Vadthanarat et al. (2018). Maximum likelihood bootstrap values greater than 70% are indicated at the nodes. The bar indicates the number of nucleotide substitutions per site. Type specimens are indicated in bold. Newly generated sequences are in blue.