Boletales » Boletaceae » Zangia

Zangia roseola

Zangia roseola (W.F. Chiu) Y.C. Li & Zhu L. Yang , in Li, Feng & Yang, Fungal Diversity 49: 129 (2011)

Pileus 24 cm in diam., hemispherical to convex, dry or slightly viscid, finely rugose, carnelian purplish red to purple red or dull red but becoming pinkish or even white towards the pileal margin, covered with white to cream or brownish pubescence when young but soon glabrous; context white to cream with purplish tinge beneath pileipellis rarely bluish when injured. Hymenophore free to subfree or sinuate around apex of stipe, white initially, pinkish to pink when mature; pores small, about 0.5 mm in diam., with scattered rust brown stains when old or bruised; tubes 510 mm in depth, concolourous with the pores.. Stipe 47×0.30.6 cm, subcylindrical or slightly attenuate upwards, base sometimes with globose bulb; surface pinkish to purplish or purple, but white to cream or yellowish at apical part and bright yellow to chrome yellow at base, whole surface covered with minute squamules, the colour corresponding to that of the stipe surface; mycelia on base of stipe chrome yellow to golden yellow; context cream to yellowish but golden yellow at base, becoming blue slowly when injured. Taste and odor not distinctive. Spore print pinkish, pink or pale purple

Basidia 2638×1015 μm, clavate, hyaline in KOH and yellowish in Melzers reagent, 4-spored, sometimes 2- spored. Basidiospores (550/20/11) 1316(17)× (5.5)67(8) μm, [Q = (2)2.142.54(2.83), Q=2.31±0.19], ellipsoid to somewhat oblong, smooth, light olivaceous to pale melleous in KOH and yellowish brown in Melzers reagent. Pleuro- and cheilocystidia 3083×518 μm, clavate to subfusiform, thin-walled, colourless and hyaline in KOH and yellowish to yellow in Melzers reagent. Pileipellis an ixohyphoepithelium, outer layer consisting of yellow to yellowish brown interwoven hyphae 46 μm in width, lower layer made up of inflated cells up to 20 μm in width arising from radially arranged, repent filamentous hyphae 36 μm in width. Pileal trama composed of broad interwoven hyphae up to 510 μm in width. Stipe dermatocystidia ventricose, fusoid ventricose, clavate, or lanceolate, pale yellow in KOH. Clamp connections absent.

Habitat: solitary to scattered, in mixed forests of Pinus armandii, P. yunnanensis, Quercus variabilis, Lithocarpus spp., Castanopsis spp., and Keteleeria spp.

Known distribution: Currently only known from southwestern China.

Index Fungorum number: IF518871

Notes: Zangia roseola is characterized by the small (24 cm in diam.), carnelian purplish red to purple red or dull red pileus, the pinkish to purple pink scabrous stipe, the pinkish to pink or purple hymenophore, and broad basidiospores (up to 7 μm). Chiu (1948) described Boletus roseolus as a new species based on the collections from Binchuan and Kunming, Yunnan Province. This species was then transferred to Tylopilus due to the colour of the hymenophore and basidiospores (Tai 1979). However, the ixohyphoepithelium pileipellis, the coarsely verrucose stipe and bluish colour changes in the stipe are different from those in the genus Tylopilus typified by T. felleus (Bull.) P. Karst. or in T. subgen. Roseoscabra typed by T. chromapes. Thus, a new combination is proposed.


Figure 1. Cladogram resulting from the combined nuclear (nrLSU, EF1-α) and mitochondrial (mtLSU, mtSSU and ATP6) DNA dataset using RAxML. RAxML and MP BS support values (>50%) are indicated above or below the branches as RAxML BS/MP BS. In Bayesian analysis, PP> 0.95 are indicated with thick branch.


Fig. 2. Spores of Zangia roseola (HKAS 51137) under SEM.. Scale bars=10 μm