. A text-book of botany for secondary schools. Botany. A TEXT-BOOK OP BOTANY case the early spring spores infecting wheat plants rather than barberry leaves; and recently it has been shown that often the summer spores siu-\-ive the severest winter and infect young wheat plants of the next season. Another well-known rust is that which attacks apple- trees and their relatives, the wild crab, hawthorn, etc. The stage on the apple-tree is the clus- ter-cup stage, the cluster-cups occurring on the under surface of the leaves; the mycelium also attacks and ruins the fruit, the cluster-cups bein
. A text-book of botany for secondary schools. Botany. A TEXT-BOOK OP BOTANY case the early spring spores infecting wheat plants rather than barberry leaves; and recently it has been shown that often the summer spores siu-\-ive the severest winter and infect young wheat plants of the next season. Another well-known rust is that which attacks apple- trees and their relatives, the wild crab, hawthorn, etc. The stage on the apple-tree is the clus- ter-cup stage, the cluster-cups occurring on the under surface of the leaves; the mycelium also attacks and ruins the fruit, the cluster-cups being seen in connection with the diseased parts. The cluster-cup spores infect the cedars, producing swellings half an inch or more in diame- ter and known as cedar- apples (Fig. 144). In the spring these cedar-apples become conspicuous, espe- cially after a rain, when the jelly-like masses con- taining the orange-colored spores swell. These spores are blown about and in- fect the apples. Attempts are made to check the ap- ple-rust by destroying the cedar-trees and by spray- ing the apple-trees, when they are putting out their leaves, with a liquid that kills such Fungi. Although rusts possess several kinds of ordinary (asex- ual) spores, no oospores (sexually formed spores) have been observed; but a process in the life-history representing a sexual act has been dis(â o^â¢(â re(l in some Fig. 144.âA 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 Coulter, John Merle, 1851-1928. New York, D. Appleton
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1906
