Diseases of plants induced by Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae diseasesofplant00tube Year: 1897 466 FUNGI IMPEKFECTI. stricted tissue will be found extending quite round the twig (Fig. 293). At these places the bark and cambium have been killed, whereas the higher portions of the twig have continued to increase in thickness. Numerous small black pycnidia break out on the bark of diseased places and give of!' small unicellular spindle-shaped couidia, which convey infection to new hosts in August
Diseases of plants induced by Diseases of plants induced by cryptogamic parasites; introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae diseasesofplant00tube Year: 1897 466 FUNGI IMPEKFECTI. stricted tissue will be found extending quite round the twig (Fig. 293). At these places the bark and cambium have been killed, whereas the higher portions of the twig have continued to increase in thickness. Numerous small black pycnidia break out on the bark of diseased places and give of!' small unicellular spindle-shaped couidia, which convey infection to new hosts in August or September. Killed branches die and dry up without casting their needles. Ph. pithya Sacc. causes a disease similar to the preceding on the Douglas fir {Pscudotsuga Donrjlasii). The pycnidia of the fungus are found on dead constricted parts of twigs, and they, as well as other symptoms of the disease, closely resemble those of Phoma ahietina. Eostrup'' defined and de- scribed it as Ph. 'pitliya Sacc, ]\Iagnus also re- cords it on branches of Pinus syhestris in Berlin botanic garden. Other species of Phoma frequent other conifers and broad- Fio. 203.—Phoma ahietina. Twig of Silver Fir show iiig the constriction characteristic of this disease dotted over with pycnidia. (After R. Hartig.) Buhm (Zeifsch. f. Forst- u. Jacjd-wesen, 1896, p. ) describes .and figures an attack of this parasite on Pseudotstuia Donglasii in North GermanJ One cannot, however, avoid suggesting some confusion between this and Ph. pithya described next. (Edit.) -E. Rostrup Undersoeqtlser over Snyltes vampes Angreb paa Skovtraeer,
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