ON GRAMINE.E 



261 



Eriksson has divided this species into a number of forms which show- 

 certain differences, chiefly biological : they are given in what follows, but 

 it must be understood that they are distinguished almost entirely by their 

 host-plants. They all show the same scattered, brownish-orange uredo- 

 sori. Some, it is true, have recidia, others are not known to have them, 

 but this is a difference which time may remove ; also Pole-Evans (1907) 

 has shown that they present minute differences in the mode of germination 

 of their uredospores. Many authors prefer to consider the biological races 

 which follow as distinct species, but if that is done it is a mistake, which 

 entails continual confusion, to retain the name P. dispersa for one of them. 



Distribution : Europe, Asia Minor, North America, and in 

 Australia (probably only introduced). 



(1) PUCCINIA SECALINA 110V. nom. 



Puccinia dispersa (sens, strict.) Erikss. Ann. Sci. Nat. ser. 8, ix. 268, 

 pi. xi, f. 1—6 (1899). Sydow, Monogr. i. 709. Fischer, Ured. 

 Schweiz, p. 357, f. 261. Klebahn, "Wirtswechs. Rostp. p. 237. 



JEcidvwm Anchusae Erikss. et Pfenning, Getreideroste, p. 210. 



2E. Asperifolii Pers. ; Cooke, Handb. p. 541 ; Micr. Fung. p. 197 p.p. 



JEcidiospores. iEcidia hypophyllous or often on the calyx 

 and fruit, seated on rounded yel- 

 lowish or reddish-yellow spots, 

 cup-shaped, with an incised revo- 

 lute margin ; spores verruculose, 

 orange, 20 — 26 p.. 



^Ecidia on Anckusa (Lycupsis) 

 arvensis, very rare, Shere, Folkes- 

 tone, Eltham, etc., August; uredo- 

 and teleutospores on Secede Cereale, 

 May— October. (Fig. 198.) 



Fig. 198. P. secalina. yEcidia 

 on leaf of Lycopsis ; teleuto- 

 spores, ou neighbouring stems 

 of Rye. 



The Brown Rust of Rye in the 

 uredo- and teleuto-stages seems to be 

 confined to that cereal. Eriksson and 

 Klebahn have proved that it can be 



transferred from species of Anchvsa to the Rye and vice-versd, but not, 

 they say, to other plants. Plowright's observation (Ured. p. 168) that 

 the secidium was produced on Anchusa by infection from a rusted bundle 

 of wheat straw is discredited by them, but possibly without sufficient 

 reason. The teleutospores are capable of germination as soon as they 

 mature ; hence the lecidium is usually met with in August and September- 



