Phylloporus pruinatus Kuan Zhao & N.K. Zeng, 2018

Zhao, Kuan, Zeng, Nian-Kai, Han, Li-Hong, Gao, Xiao-Ye, Liu, Jian-Tao, Wu, Gang, Wang, Song- Hua & Gu, Bing, 2018, Phylloporus pruinatus, a new lamellate bolete from subtropical China, Phytotaxa 372 (3), pp. 212-220 : 217-218

Phylloporus pruinatus Kuan Zhao & N.K. Zeng , sp. nov. ( Figs. 2–4 )

MycoBank: MB 827415

Etymology:— “pruinatus ” refers to the surface of the pileus covered with a thin pruina.

Diagnosis:—Characterized by its smaller size (pileus 2–3 cm in diameter), yellowish brown to reddish brown pileus with a thin white pruina, white to cream context unchanging in color when injured, white basal mycelium and slightly inflated terminal cells of the pileipellis.

Holotype: — CHINA. Anhui Province: Huangshan Mount., Yungu Temple, in a mixed forest of Pinus taiwanensis , Lithocarpus spp. and Quercus spp. , elev. 600 m, 18 July 2017, Kuan Zhao 950 (HKAS 101929).

Description:— Pileus 2–3 cm in diameter, applanate, slightly depressed at center, tomentulose, covered with a thin layer of white pruina, margin usually inflexed; surface yellowish brown (4A5–7) to reddish brown (6B6–7), unchanging in color when injured; context 0.5–1 cm thick, whitish to cream, unchanging in color when injured. Hymenophore lamellate, slightly decurrent, unchanging in color when bruised; lamellae subdistant, about 0.3 cm in height, usually anastomosing, fresh yellow (2A6–7) to golden yellow (4A5–6), unchanging in color when injured; lamellulae common, attenuate, concolorous with lamellae. Stipe 2–3 × 0.2–0.3 cm, central, subcylindric, solid; surface dry, background yellowish (2A2–3), with yellowish brown (3B6–8) to reddish brown (10C5–6) scabers, especially at the apex of the stipe; context yellowish white (1A1–2) to pale yellow (2A2), unchanging in color when injured. Basal mycelium whitish. Odor and taste indistinctive.

Basidiospores [100/2/2] 8–11(13) × 3.5–5 μm [Q = 2.00–2.57(2.86), Q m = 2.23 ± 0.15], subfusiform to ellipsoid, slightly thick-walled (<1 μm thick), yellowish brown in KOH, smooth under the light microscope, but with bacillate ornamentation under SEM ( Fig. 4 ). Hymenophoral trama slightly bilateral, made up of hyphae 4–19 μm in width, colorless to yellowish in KOH. Cheilocystidia 50–130 × 9–15 μm, ventricose-subfusiform, thin-walled, colorless in KOH, without encrustations. Pleurocystidia 70–100 × 13–17 μm, similar to cheilocystidia in shape. Pileipellis a trichoderm composed of yellowish to brownish hyphae, 5–9(12) μm wide, thin-walled; terminal cells (17)28–50(62) × (5)8–13(22) μm, subcylindrical, with obtuse apex, always with yellowish brown internal encrustations; pileal trama made up of hyphae 4–7 μm in diameter, thin-walled, colorless to yellowish in KOH. Stipitipellis composed of parallel hyphae 3.5–9(12) cm in diameter, colorless to yellowish in KOH. Amyloid reaction negative. Clamp connections absent in all tissues.

Habitat and distribution:—Solitary in mixed forest of Pinaceae and Fagaceae . Currently only known from Anhui and Yunnan Province, subtropical China.

Other materials examined:— CHINA. Yunnan Province, Dali City, Yongping County, in a mixed forest of Pinus yunnanensis , Quercus spp. and Ericaceae spp., elev. 2000 m, 31 July 2009, L.P. Tang 1043 (HKAS 74687).

Figures

FIGURE 2. Basidiomata of Phylloporus pruinatus (a–b from HKAS 101929 (holotype); image taken immediately after sectioning; c–d from HKAS 74687). Bars: a–d=1 cm. Photos by Kuan Zhao (a–b) and Niankai Zeng (c–d).

FIGURE 3. Microscopic features of Phylloporus pruinatus (a–c from HKAS 101929 (holotype); d from HKAS 74687). Drawings by Kuan Zhao. a. Basidiospores. b. Basidia and pleurocystidium. c. Cheilocystidia. d. Pileipellis.

FIGURE 4. SEM of basidiospores of Phylloporus pruinatus from dried specimen (HKAS 101929, holotype). Photos by Gang Wu.