Chiua virens (W.F. Chiu) Yan C. Li & Zhu L. Yang, in Wu et al., Fungal Diversity 81: 76 (2016)
Pileus 3–8 cm in diam., hemispherical to convex or applanate; surface green to dark green or olive-green when young, greenish yellow to mustard yellow in age, dry, usually covered with concolorous fibrillose or tomentose squamules which are not distinct until the surface is areolately cracked with age; context yellow to bright yellow, unchanging in color when bruised. Hymenophore depressed around apex of stipe; surface white when young, and becoming pinkish to pink when mature; tubes 5–20 mm long, concolorous with hymenophoral surface, unchanging in color when injured; pores angular, 1–2/mm; unchanging in color when bruised. Stipe 3–7 9 0.2–1.8 cm, subcylindrical to clavate; surface yellow to mustard yellow in the upper part, and bright yellow to chrome yellow towards base, occasionally covered with concolorous dotted-elements, unchanging in color when touched; context almostconcolorous with that of pileus, but bright yellow to chrome yellow at the base; basal mycelium bright yellow to chrome yellow. Taste and odor mild.
Basidia 20–30 9 9– μm, clavate, 4-spored, rarely 2-spored. Basidiospores (11) 11.5–13.5 9 5–5.5 μm [Q = (2.30) 2.36–2.60 (2.70), Qm = 2.47 ± 0.12], subfusiform and inequilateral in side view with slightly suprahilar depression, yellowish to brownish yellow, smooth, slightly thick-walled (up to 1 μm). Hymenophoral trama boletoid; hyphae cylindrical, 3–11 μm wide, colorless to yellowish. Cheilocystidia 20–37 9 7–9 μm, clavate with obtuse to subacute apex, usually containing yellowish to yellow pigments, thin-walled. Pleurocystidia 40–56 9 6–10 μm, subfusiform to fusoid-ventricose, sometimes with subacute apex, thin-walled. Caulocystidia forming squamules over stipe surface, ventricose, fusoid ventricose, clavate, lanceolate. Pileipellis a subcutis to trichodermium, composed of filamentous interwoven hyphae 3.5–7 μm wide with terminal cells 8–31 9 4–7 μm which are often covered with a yellowish to yellow incrustation. Pileal trama composed of colorless to yellowish interwoven hyphae up to 15 μm in width. Clamp connections absent.
Habitat: Scattered on soil in forests dominated by plants of the family Pinaceae (Keteleeria evelyniana Mast., Pinus yunnanensis Franch. or Pinus densata Mast.).
Known distribution: Currently known from East Asia.
Index Fungorum number: IF 810350
Notes: Chiua virens is characterized by the green to dark green or olive-green then greenish yellow to mustard yellow pileus, the pinkish or pink to purplish hymenophore and the upper part yellow and lower part chrome yellow stipe. Such traits are very similar to those of Chi. angusticystidiatus. Interestingly, Chi. virens is indeed clustered phylogenetically with Chi. Angusticystidiatus with high support However, Chi. angusticystidiatus differs from Chi. virens by the pink to purplish pink scabrous stipe, the hyphoepithelium pileipellis and the association with fagaceous plants. Wolfe and Bougher (1993) stated that T. chromoreticulatus has an indistinct reticulate stipe and T. piniphilus has a yellow to mustard yellow pileus. In our field investigation, it was observed that some younger basidiomata of Chi. virens do indeed have an indistinct reticulation on the stipe, and the color of the pileus varies much at different stages of development. Young basidiomata have a green to dark green or olive green pileus and the aged ones usually possess a yellow to mustard yellow pileus. Moreover, sequences from the holotype of T. chromoreticulatus, and the holotype and paratype of T. piniphilus are clustered together with Chi. virens with a little genetic variation in our multi-locus analaysis. Thus, T. chromoreticulatus and T. piniphilus are treated as the synonyms of Chi. virens.
Figure 1. Fresh basidiomata of m–o. Chiua virens (m-HKAS 56270, n-HKAS 56322, o-HKAS 52665)
Figure 2. Chiua virens (HKAS 50543). a. Cheilocystidia; b. Basidia and pleurocystidia; c. Pleurocystidia; d. Basidiospores; e. Pileus covering; f. Scabrous squamules on stipe. Scale bars = 10 μm
Wu, Gang & Li, Yan-Chun & Zhu, Xue-Tai & Zhao, Kuan & Han, Li-Hong & Cui, Yang-Yang & Fang, Li & Xu, Jianping. 2016) One hundred noteworthy boletes from China. Fungal Diversity. 81. 10.1007/s13225-016-0375-8.