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 Add this item to the list  Poria cinerescens (Bres.) Sacc.
Page number:387 
Description type:Culture description 
Description:Poria cinerescens (Bres.) Sacc.
Cultural characters: (Pl. XV, Fig. 1; Pl. XVI, Figs. 1 to 5).
Growth characters. Growth rapid plates covered in one to two weeks. Advancing zone even, hyaline, appressed. Mat white, at first appressed or submerged, with aerial mycelium thin downs or almost lacking, translucent except for numerous scattered V-shaped areas, with points directed away from inoculum, opaque because of denser growth within agar and fine woolly to farinaceous surface, later with overgrowth of slightly raised woolly or cottony mycelium beginning around edge of Petri disk and growing inward, in some isolates covering most of surface, in others restricted to band around outside. Reverse unchanged or partially bleached, the V-shaped thickenings prominent. No odor. On gallic acid agar diffusion zone vers strong, colonys 5.0-8.0 cm. diameter; on tannic acid agar diffusion zone moderately strong colonys trace to 1.5 cm. diameter.
Hyphal characters. Advancing zone: leading hyphae hyaline, thin-walled at first but walls soon becoming thickened, with rare, inconspicuous, simple septa, 3.0-7.5 µm diameter, frequently branched, the branches soon developing clamp connections. Aerial mycelium: (a) thick-walled hyphae with simple septa as in advancing zone, rare but conspicuous; (b) nodose-septate hyphae, 1.5-3.0 µm diameter; (c) chlamydospores usually numerous, terminal and intercalary, globose and subglobose, 7.5-10.5 µm diameter; (d) oidia rare in some isolates, apparently lacking in others, formed in advancing zone by fragmentation of hyphae with simple septa, 4.5-6.0 µm diameter, of varying lengths. Submerged mycelium: (a) nodose-septate hyphae and (b) rare chlamydospores as described above.
Type of rot: white laminate rot of coniferous and broad-leaved trees.
Morphological differences in the fruit bodies of Poria albipellucida and P. cinerescens, particularly in the basidiospores, which are ovate, 4.5-5.0 x 3.5-4.5 µm in the former (Cooke (60) ) and cylindric, 4.5-6.0 x 1.5-2.5 µm in the latter (Overholts (122) ) establish the existence of two species, but separation of the cultures on the basis of the diagnostic characters employed in the present study, has proved impossible. For this reason the two species have been listed together in the key, and no description or illustrations of P. cinerescens have been included, since they appear to be identical with those given for P. albipellucida. In the key P. albipellucida coincides with Polyporus resinosus in three places, with P. galactinus in one. The characteristic V-shaped thicker areas in the mat of Poria albipellucida provide a recognizable feature, and the lack of odor in this species separates it from the fragrant cultures of Polyporus resinosus. The rapid growth of cultures of Poria albipellucida on medium containing gallic acid serves to separate them from cultures of Polyporus galactinus in which growth is completely inhibited by gallic acid agar.
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