Gyroporus flavocyanescens 2021

Gyroporus flavocyanescens Yan C. Li, C. Huang & Zhu L. Yang, sp. nov.2021

MycoBank No: 838414

Holotype: China. Guizhou Province: Pan County, alt. 1700 m, 2 Jul 2008, X.L. Wu 1182 (KUN-HKAS 76966, GenBank accession numbers: MW440550 for ITS, MW442950 for nrLSU, MW452613 for atp6).

Morphological description

Sexual morph: Pileus 6–10 cm in diam., hemispherical to sub-hemispherical when young, applanate to plano-convex when mature, flavous to dull yellow or grey-yellow  when young, grey-orange to greyish-orange when mature; surface dry, nearly glabrous or somewhat fibrillose to finely tomentose, margin incurved and slightly extended; context whitish , staining strong dark blue or indigo-blue when bruised. Hymenophore adnate when young, de pressed around apex of stipe when mature; surface white when young and then grey to cream when mature, staining cyanine blue to porcelain blue when bruised; pores angular to roundish, 1–2 per mm; tubes 4–10 mm long, whitish, staining cyanine blue to porcelain blue when bruised. Stipe 4–6 × 2.5–4 cm, clavate, enlarged downwards; surface roughened, white to cream when young and then pale yellow  to concolorous with pileal surface when mature or aged; context white to cream or yellowish, spongy when young and then hollow in age, staining cyanine blue to porcelain blue when bruised. Odour indistinct and taste mild.

   Basidia 21–30 × 9–11 µm, clavate, hyaline in KOH and yellowish in Melzer’s Rea gent, 4-spored. Basidiospores [60/3/2] 8–10 × (5) 5.5–6.5 µm, (Q = 1.45–1.81, Qm = 1.59 ± 0.12), smooth, ellipsoid to somewhat broadly ellipsoid, hyaline to yellowish in KOH and primrose yellow to yellow in Melzer’s Reagent. Cheilocystidia 26–35 × 5–9 µm, clavate to subfusiform, thin-walled, hyaline in KOH and yellowish to yellow in Melzer’s Reagent. Pleurocystidia not observed. Tube trama composed of 5–9 µm wide interwoven hyphae, hyaline to yellowish in KOH, yellowish to brownish-yellow in Melzer’s Reagent. Squamules on pileus composed of 8–17 µm wide interwoven hyphae, hyaline to yellowish in KOH, yellowish to brownish-yellow in Melzer’s Rea gent; terminal cells 90–140 × 9–17 µm, clavate to subcylindrical. Clamp connections frequently present in all tissues.

Asexual morph: Undetermined

Culture characteristics:

Habitat: Scattered on soil in the tropical forests dominated by Castanea sp. (Fagaceae) and Quercus sp. (Fagaceae).

Distribution: Currently known from south western China.

GenBank Accession: ITS MW440550; LSU MW442950; atp6 452613

ITS MW440551; LSU MW442951; atp6 -

Notes: Gyroporus flavocyanescens is characterised by the flavous to dull yellow or grey-yellow and then grey-orange to greyish-orange pileus, the nearly glabrous to fibril lose to finely tomentose pileal surface, the slightly extended pileal margin, the white pileal context staining strong dark blue or indigo-blue when bruised, the white to grey or cream to yellowish hymenophore staining cyanine blue to porcelain blue when bruised, the white to cream and then pale yellow to flavous stipe, the spongy and then hollow context in the stipe, the frequent clamp connections in all tissues, the ellipsoid to somewhat broadly ellipsoid basidiospores and the distribution in tropical forests dominated by plants of the family Fagaceae.

Gyroporus flavocyanescens is morphologically similar to G. lacteus and G. pseudola cteus. Indeed, they are phylogenetically related to each other, based on our analysis of combined nrLSU + ITS dataset (Fig. 2), though it should be noted that the bootstrap support is relatively low for the relationship with G. lacteus (87%). Gyroporus lacteus has large basidiomata (9–17 cm in diam.), ochraceous pileus with scaly tomentose squamules and large cheilocystidia up to 50 × 10 µm (Vizzini et al. 2015). Gyroporus pseudolacteus has a whitish to cream white and then more or less yellowish-ochre pileus, relatively large basidia measuring 35–43 × 10–14 µm and large cheilocystidia measur ing 35–55 × 8–12 µm (Crous et al. 2017).

Reference: [1] Huang, C. ,  Zhang, M. ,  Wu, X. ,   Wu, G. ,  Xu, J. , &  Yang, Z. , et al. (2021). Cyanescentgyroporus(gyroporaceae, boletales) from china. MycoKeys, 81, 165-183.

Figure 3. d Gyroporus flavocyanes cens (KUN-HKAS 76966, type, photo by X.L. Wu) Scale bars: 2 cm. 

Figure 6. Microscopic features of G. flavocyanescens (KUN-HKAS 76966, type) a basidia b basidi ospores c cheilocystidia d pileipellis (squamules).