Lanmaoa macrocarpa N.K. Zeng, H. Chai & S. Jiang

Chai, Hui, Liang, Zhi-Qun, Xue, Rou, Jiang, Shuai, Luo, Shi-Hong, Wang, Yong, Wu, Lu-Ling, Tang, Li-Ping, Chen, Yun, Hong, Deng & Zeng, Nian-Kai, 2019, New and noteworthy boletes from subtropical and tropical China, MycoKeys 46, pp. 55-96 : 68

5. Lanmaoa macrocarpa N.K. Zeng, H. Chai & S. Jiang sp. nov. Figures 5 a–c, 11

Typification.

CHINA. Hainan Province: Qiongzhong County, Yinggeling National Nature Reserve, elev. 750 m, 28 May 2017, N.K. Zeng 3021 (FHMU 1982, holotype). GenBank accession numbers: 28S = MH879684, tef1 = MH879713.

Etymology.

Latin, “macrocarpa”, meaning the new species has a large pileus.

Description.

Basidiomata large. Pileus 10-13 cm in diameter, subhemispherical when young, then convex to applanate; surface dry, finely tomentose, brownish red (8B6-9B6); context about 2.5 cm thick in the center of the pileus, yellowish, changing blue quickly when injured. Hymenophore poroid, depressed around apex of stipe; pores subround to angular, 1-2 mm in diameter, yellow (3A5), changing blue quickly, then turning brown slowly when injured; tubes about 1.5 cm in length. Stipe 8-11 × 1.5-2 cm, central, subcylindric, solid; surface dry, brownish red (9C6), sometimes reticulate at apex; context yellow, changing blue quickly when injured; basal mycelium yellowish (2A4). Odor indistinct.

Basidia 18-28 × 6-10 μm, clavate, thin-walled, colorless to yellowish in KOH; four-spored, sterigmata 3-4 μm in length. Basidiospores [40/2/2] (9 –)10–12(– 13) × 4.5-5 μm, Q=(2.00 –)2.10–2.60(– 2.67), Qm=2.39 ± 0.16, subfusoid and inequilateral in side view with a weak or distinct suprahilar depression, elliptic-fusiform to subfusiform in ventral view, slightly thick-walled (to 0.5 μm), olive-brown to yellowish brown in KOH, smooth. Hymenophoral trama boletoid; composed of colorless to yellowish in KOH, 4.5-9 μm wide, thin- to slightly thick-walled (to 0.5 μm) hyphae. Cheilocystidia 25-42 × 7-10 μm, ventricose, fusiform or subfusiform, thin-walled, yellowish in KOH, no encrustations. Pleurocystidia 25-45 × 7-11 μm, fusiform or subfusiform, thin-walled, yellowish in KOH, no encrustations. Pileipellis a trichoderm 120-160 μm thick, composed of rather vertically arranged, nearly colorless in KOH, 4.5-6 μm wide, thin-walled hyphae; terminal cells 21-32 × 4-6 μm long, clavate or subclavate, with obtuse apex. Pileal trama made up of hyphae 3-10 μm in diameter, thin-walled, nearly colorless in KOH. Stipitipellis hymeniform about 100 μm thick, composed of thin- to slightly thick-walled (to 0.5 μm) emergent hyphae, colorless in KOH, with clavate, subclavate, fusiform, or subfusiform terminal cells (22-43 × 3-9 μm), and occasionally with scattered clavate, 4-spored basidia. Stipe trama composed of longitudinally arranged, parallel hyphae 3-8 μm wide, cylindrical, thin- to slightly thick-walled (to 0.5 μm), yellowish in KOH. Clamp connections absent in all tissues.

Habitat.

Solitary on the ground in forests dominated by Castanopsis kawakamii Hay. or C. fissa (Champ. ex Benth.) Rehd. et Wils.

Distribution.

Southeastern and southern China.

Additional specimens examined.

CHINA. Fujian Province: Sanming City, Geshikao National Forest Park, elev. 400 m, 16 August 2017, N.K. Zeng 3251 (FHMU 2212).

Note.

Lanmaoa macrocarpa is characterized by its large basidioma, brownish red pileus and stipe, thickness of hymenophore 3/5 times that of pileal context, and its association with Castanopsis spp. It is both morphologically similar and phylogenetically related to Chinese L. rubriceps N.K. Zeng & Hui Chai ( Chai et al. 2018) and one collection tentatively named " Lanmaoa sp. HKAS 52518" (Fig. 3). However, L. rubriceps has a red to crimson, orange-red pileus, pores stuffed when young, sometimes tinged with reddish when old, and smaller basidiospores measuring 8-11 × 4-5 μm ( Chai et al. 2018); careful examinations showed that Lanmaoa sp. HKAS 52518 has a smaller basidioma, a reddish to red or blackish-red pileus, and surface of stipe turning blue when injured.