236 PUCCINIA 



above, scarcely or slightly thickened, gently constricted, rounded 

 or attenuated below, smooth, brown, 2.x - 52 x20 — 26 n : pedicels 

 hyaline, short, deciduous; mcsospoivs numerous, obovate or 

 pyriform, very irregular, 22 — 36x15 — 23 fx. 



On leaves, sheaths and stems of various species of Allium, 

 A. Cepa, A. Scliuen<>]>r<isiini. A. Scorodoprasum, etc. Rather 

 uncommon. June — August. (Fig. L82.) 



Fischer describes the uredospores as pale brown, distantly waited, 

 28 — 32x2] 28 /*, and provided with three germ-pores. The secidium on 

 Allium which is usually placed with this species does not belong here. 

 The secidium on Allium ursinum is known to belong to one of the forms of 

 P. sessilis : seme, if not all, of the secidia on other species of Allium may 

 be in the same class. It was Tranzschel (Ann. Mycol. 1910, viii. 415) who 

 proved that /'. Porri is a'Hemipuccinia ; he sowed the basidiospores on 

 Allium and obtained the uredospores direct. The supposed secidium 

 is almost always found separate from the uredo- and teleutospores. There 

 is a very close alliance between P. Porri and Cm,,, ,/,,-.< inuhiquus, if indeed 

 they are not the two extremes of the same species. 



If this disease attacks cultivated onions, as it sometimes does, remove 

 and burn all diseased plants and do not sow onions on the same ground 

 again for several years. 



*o 



Distribution: Europe, Syria. 



105. Puccinia obscura Schrot. 



JEcidium Compositarum var. Bellidis DC. ; Cooke, Handb. p. 543. 



Puccinia obscura Schrot. in Nuov. Giorn. Bot. Ital. ix. 256. Plowr. 

 Ured. p. 174 ; Grevillea, xii. 86. Sacc. Syll. vii. 629. Sydow, 

 Monogr. i. 645, 898. Fischer, Ured. Schweiz, p. 237, f. 187. 



Spermogones. Amphigenous, minute, in dense roundish 

 clusters, honey-coloured. 



JEddiospores. zEcidia amphigenous, on roundish or irregular 

 yellow spots, in loose clusters or scattered, between cup-shaped 

 and cylindrical, with whitish torn margin; spores delicately 

 verruculose, yellowish, 16 — 22 fi. 



Uredospores. Sori generally hypophyllous, On irregular 

 confluent purplish-brown spots, scattered, elliptical or linear, 

 long covered by the epidermis, pulverulent, rusty-yellow ; 



