. The British rust fungi (Uredinales) their biology and classification. Rust fungi. 110 UKOMYCES clusters, cup-shaped, whitish-yellow, with a torn revolute margin; spores densely and minutely verruculose, yellowish, 15—21 /u- Fig. 62. U. Behenis. a, secidia on early leaf, 6, fficidia on later leaf, of S. infiata ; two teleiitospores. Teleutospores. Sori hypophyllous and on the stems, often surrounding the secondary secidia, irregularly scattered, gre- garious or circinate, rounded or oblong, covered for a considerable time by the lead-coloured epidermis, rather small and compact, browni
. The British rust fungi (Uredinales) their biology and classification. Rust fungi. 110 UKOMYCES clusters, cup-shaped, whitish-yellow, with a torn revolute margin; spores densely and minutely verruculose, yellowish, 15—21 /u- Fig. 62. U. Behenis. a, secidia on early leaf, 6, fficidia on later leaf, of S. infiata ; two teleiitospores. Teleutospores. Sori hypophyllous and on the stems, often surrounding the secondary secidia, irregularly scattered, gre- garious or circinate, rounded or oblong, covered for a considerable time by the lead-coloured epidermis, rather small and compact, brownish-black or black; spores subglobose or obovate, rounded above and thickened (as much as 11 ya), smooth, pale brown, 25—35 X 20—27 /j,; pedicels persistent, faintly yellow, thick, as much as 75 fx, loiig. On Silene inflata (latifolia), S. maritima. Not common. iEcidia and teleutospores, July—October. (Fig. 62.) The spots occupied by the secidia vary in colour, but the primary ones are often tinged or margined with purple. This is one of the species whose iBoidiospores are capable of reproducing the secidia, as Dietel has shown (Flora, Ixxxi. 395, 1895). Tlie primary secidia, on the earlier leaves, are in roundish groups or concentric circles, only a few being scattered. The secondary secidia, on the younger leaves, stand more often singly and are spread over a larger area ; the teleuto-sori spring from the same seoondarj'' mycelium or are formed separately. The secondary secidia are not confined to the beginning of the season, but continue to be produced till the end of autumn, being in fact the representatives of the uredo-sori. On this account this species is very interesting biologically. The primary sacidia arise from infection by comparatively few basidiospores ; the secondary arise from the more widely dispersed secidiospores of the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colorat
Size: 1915px × 1305px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambr, bookyear1913
