Phylum：Basidiomycota　>>　Class： Basidiomycetes　>>　 Order： Polyporales 
   
 
　BCRC Number： NO BCRC Number!  
   
　Scientific Name： Porostereum spadiceum
 
   
   
　Author：

Porostereum spadiceum (Pers.:Fr.) Hjortstam & Ryvarden, Syn. Fung. 4: 51. 1990..
   
 
 
 
 
　Description： Basidiocarp effuse-reflexed, orbicular and confluent, attached to substratum, membranaceous, 200-400 μm thick in section. Hymenial surface grayish brown, somewhat dark in KOH, smooth or slightly tuberculate; abhymenial reflexed zone concolorous with hymenium, tomentose; margin whitish, determinate, filamentose-fringed. Hyphal system dimitic (?); generative hyphae nodose-septate. Subiculum fairly nuiform, composed of medullary layer, with fairly loose texture; hyphae mainly oriented horizontally, sparsely ramified, usually fairly straight and distinct, hyaline near subhymenium, subhyaline or brownish near substratum, occasionally covered with minute crystals, 3-6 μm diam., with thin to ca. 1 μm thick walls, brown ones usually with thicker walls and occasionally with adventitious septa. Subhymenium differentiated from subiculum, ± thickening, with dense texture; hyphae much narrower than those of subiculum, hyaline, thin-walled. Skeletocystidia numerous, of subiculum origin, at first horizontally oriented in the subiculum and then bend downwards into hymenial layer, immersed or slightly projecting, tubular, apically slightly swollen, brownish, at least encrusted apically, length up to ca. 400 μm , 5-8 μm diam. (encrustation excluded), with 0.5-2 μm thick walls, usually with adventitious septa. Brownish lamprocystidia of hymenial layer origin may be present, but not easily distinguished from skeletocystidia on the basis of morphology. Basidia clavate, 23-30 × 5.8-6.8 μm, 4-sterigmate. Basidiospores narrowly ellipsoid, smooth, thin- Walled, (6.8-) 7.3-8.8 (-9.2) × 3.7-4.5 (-4.8) μm, IKI–, CB–.
 
 
 
 
 
　Specimens：

Taiwan. Taichung: Chiapaotai, alt. 850 m, on fallen branch of angiosperm, 6 Dec 1991, Wu 911206-41 (TNM).
 
 
 
　Habitat： null
 
 
 
　Distribution：

Rare in North Europe, otherwise widespread in Europe, Africa, Australia and Asia (according to Hjortstam and Ryvarden 1990) including Taiwan. Not known from America.
 
 
 
　References：

Wu, SH. 1992.
   
   
   
　Provided：

S. H. Wu
 
 
　Note： Usually the cystidium of the fruit body is originated either from subiculum or from hymenial layer. In this species the subiculum originated skeletocystidia are morphologically similar to the brownish lamprocystidia which comes from hymenial layer; the origin of two kinds of cystidia have also been mentioned by Hjortstam and Ryvarden (1990). We are not sure about that whether they are homologous elements from different layer, or they represent skeletocystidia and lamprocystidia respectively.