. The British rust fungi (Uredinales), their biology and classification. Uredineae. ON GRAMINE/K 263. On Triticmn vulgare. June—August. No oecidium is known to belong to it. (Fig. 200.) The Brown Rust of Wheat has been frequently so abundant in this country in its uredo-stage as to cause groat loss. The uredospores can be distinguished from those of P. graminis, when both occur upon wheat, by l)eing subglobose, not elongate-ellipsoid, and by the more numerous germ- pores which are scattered instead of forming an equatorial band ; also they appear early in spring, before those of P. graminis. S
. The British rust fungi (Uredinales), their biology and classification. Uredineae. ON GRAMINE/K 263. On Triticmn vulgare. June—August. No oecidium is known to belong to it. (Fig. 200.) The Brown Rust of Wheat has been frequently so abundant in this country in its uredo-stage as to cause groat loss. The uredospores can be distinguished from those of P. graminis, when both occur upon wheat, by l)eing subglobose, not elongate-ellipsoid, and by the more numerous germ- pores which are scattered instead of forming an equatorial band ; also they appear early in spring, before those of P. graminis. Sometimes the teleuto-sori occur on the culms, and are then arranged more or less in lines, but they are most common on the underside of the " flag" ; their spores germinate only after a winter's rest. i\lesospores are not frequent in this species. Klebahn tested the basidiospores of this Rust on forty-two likely species of plants in the hope of discovering an secidium in its life-cycle, but without any result. The uredospores were found to be capable of surviving the winter by McAlpine in Australia (where it is an introduced species), and by Carleton in the United .,, , ,1 p , , ,„o Fig. 200. P. triticina. states south of lat. 40 IS. Teleutospores. (4) PucciNiA HOLCiNA Erikss. Puccinia holcina Erikss. p. 274, pi. xiii, f. 22—5. Sydow, Monogr. i. 715. Klebahn, p. 249. Fischer, Ured. Schweiz, p. 365. On Holcus lanatus, H. mollis. June—October. Common. The uredo-stage must be carefully distinguished from that of P. coronata, which occurs on the same hosts ; the number of germ-pores at once decides the question. The uredo-sori are of a brighter colour than in the other forms of P. dispersa and stand upon conspicuous pale spots. The teleuto- spores are more rarely produced and require to be looked for closely; they resemble those of P. triticina, but are mingled with a few mesospores. (5) Puccinia agropyrina Erikss. Puccinia agropyrina Erikss. p.
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