ON CYPERACEyE 



247 



downwards, smooth, brown, darker at the apex, 45 — 80 x 18 — 

 22 yu- ; pedicels brownish-yellow, persistent, 25 — 40 /u, long. 



iEcidia on Senecio Jacobaea, May and June ; uredo- and 

 teleutospores on Garex arenaria, July — May. Rare ; Norfolk, 

 Lincolnshire, Aberdeen, Burntisland. (Fig. 190.) 



The life-history of this parasite was investigated by Plowright, who at 

 the same time demonstrated by his experimental cultures its distinctness 

 from Puccinia Cartels and P. arenariicola. Fischer records (I.e.) an 

 fecidium on Senecio Jacobaea, S. aquaticus and S. erucifolius closely 

 resembling this, but points out at the same time that C. arenaria does 

 not grow in Switzerland ; if, therefore, it is the same fungus, as it seems 

 without doubt to be, its alternate stage must occur there on some allied 

 species of Carex, such as C. disticha. 



Distribution : Germany, Holland, Switzerland (?), Russia. 



113. Puccinia arenariicola Plowr. 



Puccinia arenariicola Plowr. Journ. Linn. Soc. Bot. xxiv. 90 ; Ured. 

 p. 170. Sacc. Syll. ix. 311. Sydow, Monogr. i. 661. • 



JEcidiospores. zEcidia generally hypophyllous, in round 

 clusters on circular yellow spots which 

 are as much as 1 cm. diam. and margined 

 with purple, cup-shaped, yellowish, with 

 torn revolute margin ; spores nearly 

 smooth, yellow, 15 — 20 /t. 



Uredospores. Sori on yellowish spots, 

 linear or oblong, surrounded by the torn 

 epidermis, brown ; spores globose to 

 ovate, delicately echinulate, pale-brown, 

 18— 22/i. 



Teleutospores. Sori generally hypo- 

 phyllous, scattered or sometimes aggre- 

 gated, oblong, as much as 1 mm. long, 

 pulvinate, black ; spores clavate or ob- 

 long-clavate, rounded above where they 

 are darker and much thickened (14//.), 

 gently constricted, tapering downwards, 



smooth, brown, 40 — 65 x 14 — -22 //, ; pedicels brownish, persis 

 tent, as much as 40 //, long. 



Fig. 191. P. arenariicola. 

 iEcidia on leaf of Cen- 

 taurea nigra, produced 

 artificially in one of Plow- 

 right's cultures (reduced). 



