. The British rust fungi (Uredinales) their biology and classification. Rust fungi. ON CYPERACE^ 245 111. Puccinia silvatica Schrot. ^ddium Taraxaci K. et S. Myk. Heft. i. 80. Puccinia silvatica Schrot. in Cohn, Beitr. iii. 68. Plowr. Ured. p. 172. Sacc. Syll. vii. 627. Sydow, Monogr. i. 656. Fischer, Ured. Schweiz, p. 289, f. 211. Spermogones. In little clusters, yellowish. ^cidiospores. vEcidia hypophyllous or amphigenous, on roundish yellow or brown spots, in crowded clusters 2—5 mm. wide, rarely solitary, occa- sionally on the peduncle which they distort, cup-shaped, with torn whitish revo
. The British rust fungi (Uredinales) their biology and classification. Rust fungi. ON CYPERACE^ 245 111. Puccinia silvatica Schrot. ^ddium Taraxaci K. et S. Myk. Heft. i. 80. Puccinia silvatica Schrot. in Cohn, Beitr. iii. 68. Plowr. Ured. p. 172. Sacc. Syll. vii. 627. Sydow, Monogr. i. 656. Fischer, Ured. Schweiz, p. 289, f. 211. Spermogones. In little clusters, yellowish. ^cidiospores. vEcidia hypophyllous or amphigenous, on roundish yellow or brown spots, in crowded clusters 2—5 mm. wide, rarely solitary, occa- sionally on the peduncle which they distort, cup-shaped, with torn whitish revolute mar- gin ; spores nearly smooth, orange, 14—21 fi. [Uredospores. Sori hypophyllous, scat- tered, minute, oblong, brown; spores globose to ovate, echinulate, brown, 20—27' x 15^— 22 fi. Teleutospores. Son hypophyllous, scat- tered, minute, roundish or oblong, reaching 1 mm. in length, pulvinate, black; spores cla- vate, rounded and much thickened (up to 11 /i) above, rarely conically attenuated, gently con- stricted, tapering below, smooth, pale-brown, darker at the apex, 35—55 x 12—18/^; pedicels brownish, persistent, as much as 40 /a long.] iEcidia on Taraxacum officinale, June, July. I have seen specimens from both England and Ireland. Teleutospores on species of Carex. (Fig. 189.) The question whether F. silvatica occurs in Britain is still in the same state as in Soppitt's time. The secidium agrees with the one assigned to that species, but the teleutospores have not been found; there is no evidence that those found on Carex remota at Kew belonged to this species. The distinction of this secidium from that belonging to P. variabilis lies chiefly in the clustered peridia, which are situated on a thickened part of the leaf, the peridium-cells are arranged in evident rows and the spores form, according to Juel, longer chains. Fischer insists that the peridium cells are thickest on the outer side, while those of P. variabilis are thickest on the inner side : he
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