. Diseases of economic plants. Plant diseases. 362 Diseases of Economic Plants other trees. The wood turns brown, and crumbles under pressure. The rot extends from 3-4 m. above and below the sporophores. These are pore-bearing, triangular in Fig. 189. — Polyporus sulphureus showing effect upon wood of oak tree. After von Schrenk. The upper surface is very hard and bears fine, irregular fissures parallel to the edge. When mature, the upper surface is red-brown. The pores are barely visible without a hand lens. Soft-rot ^^^ {Polyporus obtusus Berk.). — The black oaks. Please note that

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. Diseases of economic plants. Plant diseases. 362 Diseases of Economic Plants other trees. The wood turns brown, and crumbles under pressure. The rot extends from 3-4 m. above and below the sporophores. These are pore-bearing, triangular in Fig. 189. — Polyporus sulphureus showing effect upon wood of oak tree. After von Schrenk. The upper surface is very hard and bears fine, irregular fissures parallel to the edge. When mature, the upper surface is red-brown. The pores are barely visible without a hand lens. Soft-rot ^^^ {Polyporus obtusus Berk.). — The black oaks. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Stevens, Frank Lincoln, 1871- [from old catalog]; Hall, John Galentine, 1870- [from old catalog] joint author. New York, The Macmillan company

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Keywords: ., bookcentury1900, bookdecade1920, bookpublishernewyo, bookyear1921