. The British rust fungi (Uredinales) their biology and classification. Rust fungi. ON GRAMINE^ 283. Fig. 214. P. persistens. Teleutospores. Uredospores. Sori minute, roundish or elongated, orange, on yellowish spots; spores more or less globose, minutely echinulate, yellow, 25—30 fz. Teleutospores. Sori hypophyl- lous, minute, ovate, oblong or linear, black, long covered by the epidermis; spores clavate-oblong or irregular, rounded, truncate or obliquely attenuate above, slightly thickened (4—7 /a), more or less constricted, rounded or often tapering below, smooth, brown, 50—60 x 15—20 /i; pe
. The British rust fungi (Uredinales) their biology and classification. Rust fungi. ON GRAMINE^ 283. Fig. 214. P. persistens. Teleutospores. Uredospores. Sori minute, roundish or elongated, orange, on yellowish spots; spores more or less globose, minutely echinulate, yellow, 25—30 fz. Teleutospores. Sori hypophyl- lous, minute, ovate, oblong or linear, black, long covered by the epidermis; spores clavate-oblong or irregular, rounded, truncate or obliquely attenuate above, slightly thickened (4—7 /a), more or less constricted, rounded or often tapering below, smooth, brown, 50—60 x 15—20 /i; pedicels short, hyaline, persistent. ^cidia on Thalictrum flavum, T. minus, May—July; uredo- and teleutospores on Agropyron repens, from July onwards. (Fig. 214.) The connection of these spore-forms was ascertained by Plowright and confirmed by Rostrup. The iscidia on various other species of Thalictrum may belong to the same Puocinia or to Puocinias on Agropyron caninum, Arrhenatherum elatius or even on species of Poa. There is abundant scope here for further investigation. According to Fischer the teleuto-sori are subdivided into compartments by groups of parajjhyses, in the same way as in P. Agropyri. In fact the three species, P. persistens, P. Agropyri, and P. Actaeae-Agropyri Fischer, form a natural group which should be regarded rather as biological races of one species, having their teleutospores on Triiicuni {Agropyron) and their ajcidia on Thalictrum, Clematis and Actaea respectively ; the latter {P. Actaeae- Agropyri) has not yet been found in Britain. Distribution : Europe, Siberia, Japan, Himalaya, North America. The evidence for considering the three following species as British is not yet sufficient:— 135. Puccinia Phlei-pratensis Erikss. et Henn. Puocinia Phlei-pratensis Erikss. et Henn., in Zeitschr. fUr Pflanzenkr. 1894, p. 140 ; Getreideroste, pi. 5, f. 55—6. Sacc. Syll. xi. 204. Sydow, Monogr. i. 784. Fischer, Ured. Schweiz, p. Please note
Size: 1570px × 1591px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambr, bookyear1913
