. A textbook of botany for colleges and universities ... Botany. 784 ECOLOGY trees (as the white birch, the hackberry, and various conifers) by Exoascus and by other fungi, and by the dwarf mistletoe, Arceuthobiutn pusillum. In these galls many small twigs diverge from the part infected, thus manifesting a resemblance to a broom or brush. In the case of Exoascus the mycelium hibernates, so that the fungus recurs season after season. Other important fungus galls are: the black knot of the cherry (caused by Plcrwrightia, fig. iioo); the ergot of rye and other. y^ 1100 Figs. 1097-1100. — 1097-109
. A textbook of botany for colleges and universities ... Botany. 784 ECOLOGY trees (as the white birch, the hackberry, and various conifers) by Exoascus and by other fungi, and by the dwarf mistletoe, Arceuthobiutn pusillum. In these galls many small twigs diverge from the part infected, thus manifesting a resemblance to a broom or brush. In the case of Exoascus the mycelium hibernates, so that the fungus recurs season after season. Other important fungus galls are: the black knot of the cherry (caused by Plcrwrightia, fig. iioo); the ergot of rye and other. y^ 1100 Figs. 1097-1100. — 1097-1099 gall formation in a goldenrod (Solidago serotina): 1097, the apical portion of a plant that has been attacked by an insect (Cccidomyia Solidaginis); such galls check stem elongation and prevent flowering; note the variation in leaf form; 1098, an ordinary leaf; 1099, a gall leaf or leaf-complex made up of a num- ber of coalesced leaves; IIOO, a "black knot" on a branch of the choke cherry {Prunus virginiana)^ an example of gall formation through fungal influence, the stimulating fungus being Plowrighlia morbosa; the swollen black mass is known as a stroma, and it contains many fructifications known as perithecia. grasses (caused by Claviceps), in which black protruding bodies, the sclerotia, replace the grains ; the cedar apple of Juniperus virginiana (caused by Cymnospo- rangium); and the leaf and flower galls of the Ericaceae (caused by Exobasidium). Fungi also occasion root galls in the cabbage and in the alder, and bacteria occasion galls on the roots of leguminous plants (p. 787). Sometimes fungi cause pro- nounced changes in plant habit. For example, the prostrate herbs, Euphorbia maculata and E. polygonifotia, become erect when infested with a certain rust;. 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 t
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
