. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. PHYCOMYCETES 139 of a cell (Fig. 42), which becomes a spore, or properly a spo- rangium, producing upon germination a mass of swarm spores. These spores, being dependent upon abundant moisture for their distribu- tion, may be rendered more or less ineffective by withholding water from the cranberry plants during the winter. This fungus also occurs upon other ericaceous plants more or less closely FlG. 4,. blackberry Gall: related to the cultivated cranberry. resting Spore Stage IV.
. Fungous diseases of plants : with chapters on physiology, culture methods and technique . Fungi in agriculture. PHYCOMYCETES 139 of a cell (Fig. 42), which becomes a spore, or properly a spo- rangium, producing upon germination a mass of swarm spores. These spores, being dependent upon abundant moisture for their distribu- tion, may be rendered more or less ineffective by withholding water from the cranberry plants during the winter. This fungus also occurs upon other ericaceous plants more or less closely FlG. 4,. blackberry Gall: related to the cultivated cranberry. resting Spore Stage IV. PYCNOCHYTRIUM GLOBOSUM (Schroet.) Schroet. This is a parasite common in Europe and America on many families of flowering plants. In the United States it has been found on plants growing in the peat bogs of the eastern states, some of the hosts observed being a species of violet, wild straw- berry, blackberry, and maple seedlings. It causes the development of small but noticeable yellow or reddish galls. The entrance of the swarm spore into an epidermal cell is, as indicated above, followed by general growth of the protoplasmic mass. The affected epidermal cell may become somewhat in- vaginated, but the enlargement due to the growth of the fungous cell within is such as to give the appearance of a minute gall. The resting spore is shown in Fig. 42 as it appears in mid- summer. Later there results, as indicated, the sporangial sorus, each sporangium of which, upon germination, produces the char- acteristic uniciliated swarm spores. V. CHYTRIDIALES: OTHER SPECIES Among other Synchytriaceae more or less commonly found in the United States are Synchytrium decipiens Farl. on the hog peanut, Amphicarpa monoica; Synchytrium fulgens Schroet. on the evening primrose, (Enothcra biennis; Pycnochytrium aureum. (Schroet.) Schroet. occurring upon numerous hosts ; and Pycno- chytrium Myosotidis (Kiihn) Schroet. on certain Boraginacese and Rosaceas. In a different family, Oochytriaceee, may be
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Keywords: ., bookauthorduggarbe, bookcentury1900, bookdecade1900, bookyear1909
