118 UROMYCES 



The connection of the aacidium with tlie later stages seem- not yet to 

 have been experimentally demonstrated : but McAlpine found th( 

 on young plants <4 /'. aviculare along with the other spore-forms. In 

 Europe, etc. it is recorded on many other species of Polygonum. 



This species is said to occur also on Rumex Aeetosella on the continent, 

 and should he looked for here on that host. If so, there would be three 

 species i,n /,'. Aeetosella to he considered : U. Polygoni which has verrucu- 

 lo8e uredospores and smooth teleutospores ; U. Acetosae which is distin- 

 guished by having teleutospores beset with a few minute warts arranged in 

 lines ; while Pttccinia Acetosae has aculeolate uredospores and teleutospores 

 with many delicate warts. 



Distribution : World-wide. 



30. Uromyces Lilii Fckl. 



Caeoma Lilii Link, Sp. PI., ii. 8. 



Uromyces Lilii Fckl. Symh. Myc. Nachtr. iii. 16. Sydow, Monogr. ii. 



277. Fischer, Ured. Schweiz, p. 6, f. 5. Grove, Journ. Bot. 1911, 



p. 368. 

 U. Erythronii DC. ; Sacc. Syll. vii. 564 p.p. Wild Fauna and Flora 



of Kew, p. 163 (non U. Erythronii Pass.?). 

 Xigredo Lilii Arthur, X. Amer. Fl. vii. 242. 



Spermogones. Dispersed among the secidia, brownish- 

 yellow. 



jEcidiospores. ^-Ecidia amphigenous, usually hypophvllons, 

 or even on the petioles and stems, seated on lanceolate 

 yellowish spots, in rounded or elongated groups of very different 

 sizes, and often extending widely, more or less crowded, for 

 a long time hemispherical and closed, at length opening by a 

 central pore, but scarcely cup-shaped, margin not revolute, 

 about \ mm. diam. yellow ; spores densely and minutely 

 verruculose, yellowish, 22—35 x 18 — 26 /a ; epispore 3 /a thick 

 or less. 



Teleutospores. Sori amphigenous, usually hypophyllous, on 

 large yellowish spots, scattered or collected in groups, rounded 

 or oblong, elongated on the petioles, at first covered by the 

 epidermis, which at length splits, large, pulverulent, dark- 

 brown ; spores globose to oblong or pyriform, rounded above, 

 with a prominent hyaline papilla, covered when mature with 

 short ridges w T hich are often disposed in lines more or less 



