. Botany for agricultural students . Botany. LICHENS 379 from a single cell, as in Yeast, to a massive mycelium which in some cases takes no definite shape while in others it forms a definitely shaped fruiting body. In parasitic forms the mycehum sometimes runs through the tissues of the hosts, and sometimes is chiefly superficial, sending only haustoria into the Fig. 331. —Apple attacked by the Bitter Rot Fungus, Glomerella rufomaculans. After Alwood. The spores are of two kinds, conidiospores and ascospores. The conidiospores are borne free on projecting hyphae, and grow directly into


. Botany for agricultural students . Botany. LICHENS 379 from a single cell, as in Yeast, to a massive mycelium which in some cases takes no definite shape while in others it forms a definitely shaped fruiting body. In parasitic forms the mycehum sometimes runs through the tissues of the hosts, and sometimes is chiefly superficial, sending only haustoria into the Fig. 331. —Apple attacked by the Bitter Rot Fungus, Glomerella rufomaculans. After Alwood. The spores are of two kinds, conidiospores and ascospores. The conidiospores are borne free on projecting hyphae, and grow directly into hyphae upon germination. The ascospores, the characteristic spores of the group, are borne in asci which are usually produced within a fruiting body or ascocarp, which may be an open structure or a closed one. In controlling the disease-producing forms one must reckon with conidiospores and ascospores. Lichens Lichens are very common structures which form splotches on stumps, tree trunks, rocks, old boards, etc., and some grow upon the ground. Figure 332 shows an Apple twig covered with Lichens. They may appear as a crust covering the support; or they may have flat lobed bodies like the one shown in Figure 333;. 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 Martin, John N. (John Nathan), b. 1875. New York : John Wiley & Sons, Inc.


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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919