. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 44 REACTION or HOST TO PARASITIC ATTACK. to increase in the actual wood elements. This is the case in twigs of silver fir witches' brooms, in young swellings of juniper attacked by Gyvinosporangium, and in the thickened twigs of Albizzia resulting from Uromyces Tepperianii^ (^ig- 181). There may be, however, a distinctly increased growth of the wood. Thus, with attacks of Gymnosporangium frequenting juniper, especia
. Diseases of plants induced by cryptogamic parasites : introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae . Plant diseases; Parasitic plants; Fungi. 44 REACTION or HOST TO PARASITIC ATTACK. to increase in the actual wood elements. This is the case in twigs of silver fir witches' brooms, in young swellings of juniper attacked by Gyvinosporangium, and in the thickened twigs of Albizzia resulting from Uromyces Tepperianii^ (^ig- 181). There may be, however, a distinctly increased growth of the wood. Thus, with attacks of Gymnosporangium frequenting juniper, especially G. sdbinae, there is often a marked thickening of branches due to increase in the xylem-elements. Again, one finds cankers due to Aecidium, elatimtm, accompanied by stem- swellings with a diameter twice or three times that of the normal, and in which the bark and bast form but a thin layer in proportion to the part made up by the wood. Exceptionally striking are the gigantic woody knots formed on the Japanese Pinus densifiora, and P. Thunbergii affected by Peri- dermium giganteum (Fig. 15). Wakker found that mu- cilage canals of Ehamnus Frangula affected by Aeci- dium were not so well developed as in normal twigs. Eesin-canals are often irregularly formed and ab- Fin. 15.âWood-swelling on Pinus dmsijlora, attacked normally multiplied in COU- at this place by Peridermium giganteum. J natural size. "^ (r. Tubeuf phot.) seouence of parasites. The (On PiwiM rAwre&er^iistilllargerexamplesinayoccur.) â *â ^ resin-canals of the spruce were found by Hartig to be so numerous in plants attacked by Agaricus ruelleus that an abnormal quantity of resin is produced in the wood, and flows from the diseased roots; hence has arisen the name " resin-glut" or " resin-flux " by which the disease has long been known. A particularly noticeable flux of resin takes place from pine-bark in presence of Peridermium pini; the mycelium grows in the medullary rays and res
Size: 1735px × 1440px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherl, booksubjectfungi
