ON GRAMINE.E 



283 



Fig. 214. P. persistens. 

 Teleutospores. 



Uredospores. Sori minute,, roundish or elongated, orange, 

 on yellowish spots; spores more or 

 less globose, minutely echinulate, 

 yellow, 25—30 p,. 



Teleutospores. Sori hypophyl- 

 lous, minute, ovate, oblong or 

 linear, black, long covered by the 

 epidermis ; spores clavate-oblong 

 or irregular, rounded, truncate 

 or obliquely attenuate above, 

 slightly thickened (4 — 7 /jl), more 

 or less constricted, rounded or 

 often tapering below, smooth, 

 brown, 50 — 60 x 15 — 20 //. ; pedicels short, hyaline, persistent. 



/Ecidia on Thalictrum flavum, T. minus, May — July; uredo- 

 and teleutospores on Agropyron repens, from July onwards. 

 (Fig. 214.) 



The connection of these spore-forms was ascertained by Plowright and 

 confirmed by Rostrup. The secidia on various other species of Thalictrum 

 may belong to the same Puccinia or to Puccinias on Agropyron caninum, 

 Arrhenatlierum elatius or even on species of Poa. There is abundant scope 

 here for further investigation. According to Fischer the teleuto-sori 

 are subdivided into compartments by groups of paraphyses, in the 

 same way as in P. Agropyri. In fact the three species, P. persistens, 

 P. Agropyri, and P. Actaeae- Agropyri Fischer, form a natural group 

 which should be regarded rather as biological races of one species, having 

 their teleutospores on Triticum {Agropyron) and their pecidia on 

 Thalictrwm, Clematis and Aetaea respectively ; the latter (P. Actaeae- 

 Agropyri) has not yet been found in P>ritain. 



Distribution : Europe, Siberia, Japan, Himalaya, North 

 America. 



The evidence for considering the three following species as 

 British is not yet sufficient : — 



135. Puccinia Phlei-pratensis Erikss. et Henn. 



Puccinia Phlei-pratensis Erikss. et Henn., in Zeitschr. fiir PHanzenkr. 

 1894, p. 140 ; Getreideroste, pi. 5, f. 55—6. Sacc. Syll. si. 204. 

 Sydow, Monogr. i. 784. Fischer, Ured. Schweiz, p. 260. 



