White rots occur also in wood products such as utility poles. Some of the most damaging fungi associated with white rots are Phellinus pini, Armillariella mellea, Fomitopsis annosa, Ganoderma applanatum, Oxyporus populinus, Phellinus igniarius, Innotus glomeratus, I. obliquus , and Echinodontium tinctorium. Figure 95 Closeup of brown rot in pine Brown rot. The cellulose is digested preferentially, and the lignin is only altered slightly in this type of rot. Brown rots have a shrunken cubical appearance.
Brown rots occurs mostly in gymnosperms and in wood products.
Lentinus lepideus, and Polyporus betulinus. Polyporus sulphureus and Fomes pinicola are examples of fungi that cause the less common brown rot in angiosperms. The S 2 layer of the middle cell wall is digested by some microorganisms. Many variations occur. The causal fungi are usually nonhymenomycetes- Phialophora, Penicillium, Chaetomium , etc.