. The fungi which cause plant disease . Plant diseases; Fungi. 376 THE FUNGI WHICH CAUSE PLANT DISEASE P. cerasi Ces. is a hemi-type on cherries in Southern Europe. P. ribis-caricis Kleb. I on Ribes. II and III on Carex. Klebahn -^* differentiates five species of Puccinia on Ribes be- longing to the Ribis-Carex group. These are P. pringsheimiana (^E. grossulariffi.) P. ribis-pseudocyperi, P. ribis nigri-acutje, P. ribis nigri-paniculatiE and P. magnusii. P. asparagi D. C.^^s-^w I. Peridia in elongated^ patches upon the stems and larger branches, short, edges erect, toothed. Spores orange-ye
. The fungi which cause plant disease . Plant diseases; Fungi. 376 THE FUNGI WHICH CAUSE PLANT DISEASE P. cerasi Ces. is a hemi-type on cherries in Southern Europe. P. ribis-caricis Kleb. I on Ribes. II and III on Carex. Klebahn -^* differentiates five species of Puccinia on Ribes be- longing to the Ribis-Carex group. These are P. pringsheimiana (^E. grossulariffi.) P. ribis-pseudocyperi, P. ribis nigri-acutje, P. ribis nigri-paniculatiE and P. magnusii. P. asparagi D. C.^^s-^w I. Peridia in elongated^ patches upon the stems and larger branches, short, edges erect, toothed. Spores orange-yellow, round, very finely echinulate, 15-26 ju in diameter. II. Uredinia brown, flat, small, long covered by the epidermis. Spores irregu- larly round or oval, clear-broviTi, echinu- late. 18-25 X 20-30 M- III. Telia black-brown, compact, pul- vinate, elongate or roimded, scattered. Spores oblong or clavate, base rounded, apex thickened, darker, central con- striction slight or absent, deep chest- nut-brown, 35-50 X 15-25 m- Pedicels persistent, colorless or brownish, as long as or longer than the spores. An autoecious eu-type on Asparagus, cultivated and wild. The fungus has been known in Europe since 1805 but did not attract attention in the United States until 1896 in New Jersey ^^^ when it began its devastating westward migration ^^^ across the country reaching California in 1900 or 1901. The aecial stage appears in early spring; the seciospores may germinate at once or if dry remain viable for several weeks, their germ tubes penetrating the host in most cases stomatally. The uredinia appear in early summer soon after or with the aecial stage and, wind borne, distribute the fungus. The uredinio- spores remain viable a few months when dry. The telial stage appears late in the season and germinates only after hibernation. Unicellular spores, mesospores, are sometimes Fig. 272.—Section through black nist pustule, show- ing teliospores of P. as- paragi. After Ple
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
