Butyriboletus huangnianlaii N.K. Zeng, H. Chai & Zhi Q. Liang

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 : 61-62

1. Butyriboletus huangnianlaii N.K. Zeng, H. Chai & Zhi Q. Liang sp. nov. Figures 4a, b, 7

Typification.

CHINA. Fujian Province: Sanming City, Geshikao National Forest Park, elev. 420 m, 16 August 2017, N.K. Zeng 3246 (FHMU 2207, holotype). GenBank accession numbers: 28S = MH879689, ITS = MH885351, tef1 = MH879718, rpb2 = MH879741.

Etymology.

Latin, “huangnianlaii” is named after Chinese mycologist Nian-Lai Huang, in honor of his contribution to mycology.

Description.

Basidiomata medium-sized to large. Pileus 5-11 cm in diameter, convex to applanate; surface dry, finely tomentose, pale brown (5D1-4D2), brown to reddish brown (5C2-6C2); context 0.6-2.2 cm thick in the center of the pileus, yellowish to yellow, changing blue quickly when injured. Hymenophore poroid, adnate or slightly depressed around apex of stipe; pores angular, about 0.5 mm in diameter, yellowish white (30A2) to yellowish brown (4A4), changing blue quickly when injured; tubes 0.4-0.8 cm in length. Stipe 4.5-8 × 1.3-2.5 cm, central, subcylindric, solid; surface dry, yellowish (30A2) when young, then brownish red (8D5), reticulate nearly to base; reticulum yellowish (1A2) when young, then brownish red (8D5); context yellowish to yellow, changing blue quickly when injured; basal mycelium white (1A1). Odor indistinct.

Basidia 20-31 × 6-9 μm, clavate, thin-walled, colorless to yellowish in KOH; four-spored, sterigmata 3-4 μm in length. Basidiospores [40/2/2] (7 –)7.5–10.5(– 11) × 3-4 μm, Q=(2.00 –)2.14–2.86(– 3.14), Qm=2.51 ± 0.27, 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, 3-10 μm wide, thin- to slightly thick-walled (to 0.5 μm) hyphae. Cheilocystidia 32-53 × 7-12 μm, fusiform or subfusiform, thin-walled, yellowish in KOH, no encrustations. Pleurocystidia 40-60 × 8-13 μm, fusiform or subfusiform, thin-walled, yellowish in KOH, no encrustations. Pileipellis a trichoderm about 110 μm thick, composed of slightly interwoven, nearly colorless in KOH, 4-6 μm wide, thin-walled hyphae; terminal cells 30 –50× 4-8 μm, clavate or subclavate, with obtuse apex. Pileal trama made up of hyphae 8-12 μm in diameter, thin-walled, colorless in KOH. Stipitipellis hymeniform about 120-140 μm thick, composed of thin- to slightly thick-walled (to 0.5 μm) emergent hyphae, colorless to yellowish in KOH, with clavate, subclavate, fusiform or subfusiform terminal cells (15-45 × 4-9 μm), and occasionally with scattered clavate, 4-spored basidia. Stipe trama composed of longitudinally arranged, paral lel hyphae 3.5-7 μm wide, cylindrical, thin- to slightly thick-walled (up to 0.5 μm), colorless to yellowish in KOH, parallel hyphae. Clamp connections absent in all tissues.

Habitat.

Scattered on the ground in forests dominated by Castanopsis kawakamii Hay.

Distribution.

Southeastern China.

Additional specimens examined.

CHINA. Fujian Province: Sanming City, Geshikao National Forest Park, elev. 420 m, 16 August 2017, N.K. Zeng 3245 (FHMU 2206).

Note.

Butyriboletus huangnianlaii is characterized by a medium-sized to large basidioma, pileal surface densely covered with pale brown to reddish brown squamules, smaller basidiospores, and its association with fagaceous trees. It is both morphologically similar and phylogenetically related to But. pseudospeciosus and But. roseoflavus (Fig. 1). However, But. pseudospeciosus , originally described from Yunnan Province of southwestern China, has a tomentose pileus without a reddish tinge, surface of pileus and stipe promptly staining blue when bruised, narrower cystidia and longer basidiospores measuring 9-11 × 3.5-4 μm ( Wu et al. 2016a); But. roseoflavus , originally described from Zhejiang Province of southeastern China, has a pinkish to purplish red or rose-red pileus with tomentose surface, longer basidiospores measuring 9-12 × 3-4 μm, and its association with Pinus spp. ( Arora and Frank 2014; Li et al. 2014; Wu et al. 2016a).