Hymenochaetales » Hymenochaetaceae » Pseudoinonotus

Pseudoinonotus dryadeus

Pseudoinonotus dryadeus (Pers.) T. Wagner & M. Fisch. 2001, in Dai, Y.C., Fungal diversity, 45, 131-343 (2010)

Basionym: Boletus dryadeus Pers. [as 'drijadeus'], Observationes mycologicae (Lipsiae) 2: 3 (1800)

Diagnosis: Fruitbody Basidiocarps annual, pileate, solitary, hard corky when dry. Pileus dimidiate, projecting up to 10 cm, 15 cm wide and 4 cm thick at base. Pileal surface yellowish brown to dull brown, azonate, velutinate to smooth with age; margin greyish brown, obtuse to acute. Pore surface greyish brown; pores circular to angular, 46 per mm; dissepiments thin, entire to slightly lacerate. Context yellowish brown to umber-brown, corky to fibrous, concentrically zonate, up to 1 cm thick. Tubes greyish brown, paler than context, fibrous to fragile, up to 1 cm long. Hyphal structure Hyphal system monomitic; generative hyphae simple septate; tissue darkening but otherwise unchanged in KOH. Context Generative hyphae varying from hyaline and thin-walled to yellowish and fairly thick-walled, frequently branched and septate, straight, regularly arranged, 5.58 μm in diam; hyphoid setae rare to frequent, arising from thick-walled generative hyphae, very thick-walled, dark brown, occasionally septate, a few hundreds of μm long, 7.519 μm in diam. Tubes Tramal hyphae varying from hyaline and thin-walled at dissepiment edges to yellowish brown and fairly thick-walled deeper in the trama, occasionally branched, frequently septate, straight, parallel along the tubes, 3.56 μm in diam. Setae frequent to rare, ventricose, dark brown, thick-walled, very sharp-pointed, 2335×1015 μm; basidia barrel-shaped, with four sterigmata and a simple septum at the base, 10.514×810 μm; basidioles dominant in hymenium, in shape similar to basidia, slightly smaller. Spores Basidiospores globose to ovoid, hyaline, thick-walled, smooth, dextrinoid in Melzers reagent, strongly CB+, (6.5–)78.5(–9)×(5.5–)68(–8.2) μm, L=7.8 μm, W=7.2 μm, Q=1.08 (n=30/1).

Index Fungorum Number: IF474675

Notes: Pseudoinonotus dryadeus is typical of Fomitiporia robusta in microscopic characters, and both species grow on angiosperm trees, especially on Quercus, but the latter has a perennial habit, and its hyphal structure is dimitic with abundant skeletals. Pseudoinonotus dryadeus is a rather common species in Europe and North America (Ryvarden & Gilbertson 1993; Gilbertson & Ryvarden 1986), but it is rather rare in China. 

Figure 1. Microscopic structures of Pseudoinonotus dryadeus. a basidiospores; b setae; c hyphoid setae from context; d hyphae from context; e hyphae from trama


Dai, Y.C. (2010). Hymenochaetaceae (Basidiomycota) in China. Fungal diversity, 45, 131-343.

Gilbertson, R.L., & Ryvarden, L. (1986). North American polypores 1. Fungiflora, Oslo, pp 1436.

Ryvarden, L., & Gilbertson, R. L. (1993). European Polypores, Part 1. Synopsis Fungorum, 6, 1-387.


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