Tricholomopsis yunnanensis (M. Zang) L.R. Liu, Yan C. Li & Zhu L. Yang, 2022

Liu, Li-Rong, Wang, Geng-Shen, Jia, Liu-Kun, Kang, Ju-Qing, Yang, Zhu-Liang & Li, Yan-Chun, 2022, Type studies on two Paxillus species (Paxillaceae, Boletales) described from China, Phytotaxa 530 (2), pp. 177-188 : 184-185

Tricholomopsis yunnanensis (M. Zang) L.R. Liu, Yan C. Li & Zhu L. Yang , comb. nov., Figs. 3d–f , 5a–e .

MycoBank: MB840444

Basionym: Paxillus yunnanensis M. Zang, Acta Microbiol. Sin. 18 (4): 281, Pl. I: 1–5, 1978.

Protoglogue of Paxillus yunnanensis ( Zang & Zeng 1978) : “Pileus centralis vel subexcentricus, 5.5–9.5cm diam., convexus dein pulvinato-expanus sinuosus, siccus minute villosoto-mentosus dein minute cutifractus, primo fuscopurpureus, dein purpureobadius vel cervinobrunneus; margine tenui, ivnoluto. Stipes 7–13 × 3–5 cm, cylindricus, bulbosus basim versus incrassatus, tortuosus, laevigatus et striatus, raro attenuatus; apice flavidus vel pallidus, basim versus purpureo-brunneus, basi fuscus. Lamellae distantes, decurrentes, crassae, flavido-albidae dein citrino-flavidae, interstitiis venosis. Hyphae cuticularum pilei filamentosae, septatae. Basidiosporae ovoideae vel globosae, 3.8–4.5 × 2.5–3 μm, pallido-flavae, laeves. Basidia 4-sporigera, rarissime 2-sporigera. Pleurocystidia30–45 × 7–10 μm, clavata. Cheilocystidia 65–90 × 5–20 μm, cylindricae vel fusiformia, fasciculata. Caro flavidula, oder nullus et sapor subnullus.”

Description:— Basidiomata ( Fig. 3 d-f) medium-sized. Pileus 4.1–9.5 cm in diam., dry, convex to hemispherical when young, then convex to plano-convex when mature, margin incurved; surface normally covered by red-violet (10D6–7) to red-brown (8D7–8) fibrils, dense in center and sparse towards margin, margin always cracked with cream yellow (1A1–2) background exposed when mature. Stipe cylindrical, 7–13 × 2.1–5 cm, clavate to twisted, enlarged towards base, pale lemon-yellow (2–3A2) to cream yellow (1A1–2), always covered with red-violet (10D6–7) to redbrown (8D7–8) fibrils. Lamellae adnexed, crowded, unequal, pale yellowish cream (2A2–3) when young, dark brown (6D7) when mature. Context in pileus and stipe pale yellow. Taste and odor mild, unchanging in color when bruised.

Basidiospores ( Fig. 5a ) [80/4/4] (4.5) 5–7.5 (8) × (3.5) 4–6 (6.5) μm [Q = 1–1.5 (1.57), Q m = 1.24 ± 0.16], subglobose to broadly ellipsoid, sometimes spherical or ellipsoid, smooth, hyaline in water and 5 % KOH, without color change in Melzer’s Reagent (non-dextrinoid), thin-walled. Basidia ( Fig. 5b ) 22–29 × 6–8 μm, clavate to narrowly clavate, 4-spored, subhyaline in water and 5 % KOH, with small guttules and fine granular content. Cheilocystidia ( Fig. 5c ) 60–195 × 11–39 μm, extremely large and common, fusiform, hyaline or pale yellowish brown in KOH, often in clusters and with a narrow pedicel. Pleurocystidia ( Fig. 5d ) 30–50 × 5–7 μm, subfusiform or cylindrical to narrowly clavate, thin-walled, often slightly flexuous, with a pale yellow, homogeneous or fine granular content, rarely ventricose. Hymenophoral trama composed of filamentous hyphae 2–8 μm wide, thin-walled, colorless to pale yellowish in KOH. Pileipellis ( Fig. 5e ) a palisadoderm, composed of vertically arranged hyphae 8.5–16 μm wide, colorless or with violetbrown or yellow-brown contents in KOH; terminal cells 55–160 × 10–24 μm, narrowly fusiform to subclavate with obtuse apex, sometimes with mucronate apex. Clamp connections present in all tissues.

Habitat and distribution:—Solitary or scattered on the ground in the forests dominated by plants of Pinus ; currently known from southwestern China.

Specimens examined:— CHINA. Yunnan Province: Kunming, Heilongtan Park , in forests dominated by Pinus yunnanensis , alt. 1900 m, 8 August 1974, W.Q. Yin 101-HK931 ( KUN-HKAS 28976, type) ; Kunming, Kunming Institute of Botany , alt. 1980 m, 29 August 2005, J.F. Liang 271 ( KUN-HKAS 48887) ; Kunming, Yeya Lake , alt. 2000 m, 1 September 2013, Z.L. Yang 5757 ( KUN-HKAS 80034) ; Kunming, Songming County, Dianyuan Town , Liangwangshan Jiaochang Dam , alt. 2600 m, 23 July 2016, R. Zhang 390 ( KUN-HKAS 93555) .

Figures

FIGURE 3. Photos of the collections. a-c. Boletinellus rhytidophyllus (KUN-HKAS 113221, photos by Liu-Kun Jia); d-f. Tricholomopsis yunnanensis (d. KUN-HKAS 80034, photo by Zhu L. Yang; e. KUN-HKAS 48887, photo by Jun-Feng Liang; f. KUN-HKAS 93555, photo by Rui Zhang).

FIGURE 5. Microscopic features of Tricholompsis yunnanensis (KUN-HKAS 93555). a. Basidiospores; b. Basidia; c. Cheilocystidia; d. Pleurocystidia; e. Pileipellis. Scale bars = 10 μm. Drawings by: Li-Rong Liu.