Hymenochaetales » Hymenochaetaceae » Asterodon

Asterodon ferruginosus

Asterodon ferruginosus Pat. 1894, in Dai, Y.C., Fungal diversity, 45, 131-343 (2010)

            Diagnosis: layer growing over the previous one, resupinate, up to several metres long, 40 cm wide, and 5 mm thick. Hymenophore densely covered by spines, grey to greyish brown; spines subulate, yellowish cinnamon, greyish brown or reddish brown, fragile; margin arachnoid or fibrillose, whitish to yellowish when actively growing. Subiculum dark brown, soft felty, up to 1 mm thick. Hyphal structure Hyphal system dimitic; generative hyphae with frequent septa; generative hyphae simple septate; tissue darkening but otherwise unchanged in KOH. Context Generative hyphae hyaline to pale yellowish, thin- to slightly thick-walled, straight, frequently branched at right angle, 2.5–4 μm in diam; skeletal hyphae yellowish brown, thick-walled with a wide lumen, more or less flexuous, 2.8–4.5 μm in diam, most of them ending in a seta. Asterosetae abundant in subiculum, mostly with three to five branches; branches subulate, thick-walled with a distinct lumen, rust-brown, 60–110 μm long. Tubes Tramal hyphae similar to those in subiculum; both asterosetae and subulate simple setae abundant, sometimes penetrating out of hymenium. Cystidia and cystidioles absent; basidia clavate, with four sterigmata and a simple basal septum, 10–14×4.5–7 μm; basidioles in shape similar to basidia, but slightly smaller. Spores Basidiospores ellipsoid, hyaline, fairly thick-walled, smooth, usually bearing a guttule, IKI–, CB+, (5–)5.1–7.2 (–7.5)×(3.1–)3.4–4.4(–4.5) μm, L=6.16 μm, W=3.82 μm, Q=1.61 (n=30/1).

Index Fungorum Number: IF170348

Notes: The hyphal structure and basidiospores of Asterodon ferruginosus are very similar to those of Inonotopsis subiculosa (Peck) Parmasto, and the two species even have similar ecology. However, they are not very closely related (Wagner 2001; Wagner & Fischer 2002). Inonotopsis Parmasto lacks asterosetae, and its hymenophore is poroid. Asterodon ferruginosus is widely distributed in temperate and boreal forests in Northern Hemisphere.

Figure 1.  A basidiocarp of Asterodon ferruginosus

 

 

Figure 2.  Microscopic structures of Asterodon ferruginosus. a basidiospores; b asterosetae; c hyphae from trama; d hyphae from context

 

References:

Dai, Y. C. (2010). Hymenochaetaceae (Basidiomycota) in China. Fungal diversity, 45(1), 131-343

Wagner T (2001) Phylogenetic relationships of Asterodon and Asterostroma (Basidiomycetes), two genera with asterosetae. Mycotaxon 79:235–246

Wagner, T., & Fischer, M. (2002) Classification and phylogenetic relationships of Hymenochaete and allied genera of the Hymenochaetales, inferred from rDNA sequence data and nuclear behaviour of vegetative mycelium. Mycological Prog 94, 93–104.

 

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