Phylum：Basidiomycota　>>　Class： Basidiomycetes　>>　 Order： Russulales 
   
 
　BCRC Number： NO BCRC Number!  
   
　Scientific Name： Acanthofungus rimosus
 
   
   
　Author：

Acanthofungus rimosus Sheng H. Wu, Boidin & C.Y. Chien, Mycotaxon 76: 155. 2000..
   
 
 
 
 
　Description： Basidiocarp pulvinate, at first forming small orbicular patches, then broadened and significantly thickened as a pulvinate form, up to 5 mm thick in section. The thickened basidiomata composed of numerous growth layers. The broadened basidiomata neighbor with adjacent ones; eventually the appearance of the basidiomata is deeply cracked, as if composed of many pieces. Basidioma attached the substratum by a narrow base. Hymenial surface ivory-colored, smooth, farinaceous; margin abrupt. Abhymenial surface brown, glabrous, zonate. Context whitish. Hyphal system monomitic; hyphae nodose-septate. Subiculum composed of a thin basal layer, with compact texture; hyphae horizontal, glued together, colorless, 2.5-4.5 μm diam., thick-walled. Hymenial layer differentiated from the subiculum, with compact texture; hyphae mainly vertical, colorless, usually glued together and indistinct, narrower than those of subicular hyphae, thin-or slightly thick-walled. Crystal masses fairly abundant in the thickening subhymenium near hymenium. Gloeocystidia numerous, arranged in the thickening subhymenial palisade, tubular or cylindrical, may exceed 100 μm long, 5-12 μm diam., slightly thick-walled when young, with 0.6-1.2 μm thick walls when old, SA+, with many secondary septa in old gloeocystidia, colorless, but become brownish towards old hymenial surfaces and brown lateral sides of basidioma. Acanthophyses numerous, palisadely arranged at hymenial surface and lateral sides, cylindrical or clavate, with obtuse or acute apices, bearing numerous 1-2 μm long aculei for apical halves, 17-40 × 3-7 μm (aculei excluded), slightly thick-walled towards apices, colorless, the brownish and thick-walled ones present in old hymenial surfaces and brown lateral sides. Basidia clavate, 30-40 × 5.5-7 μm, 4-sterigmate. Basidiospores ellipsoid, adaxially slightly concave, bearing a minute apiculus, smooth, thin-walled, with fairly homogeneous contents, colorless to brownish, 6-8 × 4-5 μm, IKI bluish black, CB－, binucleate.
 
 
 
 
 
　Specimens：

Taiwan. Taichung. Malin, alt. 660 m, on a white-pocket rot wood of Calocedrus formosana, 24 Jan 1996, Wu 9601-1 (TNM, holotype).
 
 
 
　Habitat： null
 
 
 
　Distribution：

Taiwan.
 
 
 
　References：

Wu, SH et al. 2000.
   
   
   
　Provided：

S. H. Wu
 
 
　Note： In possessing characters of pulvinate basidiomata, clamped hyphae, gloeocystidia, acanthophyses, and amyloid basidiospores, this species could be treated in the broad sense of the genus Aleurodiscus J. Schr ?t. However, delimitation of the genus Aleurodiscus is controversial among mycologists. Stereum ahmadii Boidin shares many of the same features with this species, but is distinguished from the latter in having smaller basidiospores. Acanthophysium thoenii is also similar to this species and S. ahmadii by the same features, but differs in having larger basidiospores. Therefore, Acanthofungus rimosus, A. thoenii, and S. ahmadii should be placed in the same genus. The genus accommodating three species share the similar characters of rot type and phenoloxidase reaction with the genus Xylobolus P. Karst., but in contrast in having clamped hyphae and heterocytic nuclear behavior. Nuclear behavior of Xylobolus is holocoenocytic. The differences in the hyphal septation and nuclear behavior permit us to treat the three species in the new genus Acanthofungus.