257 



ON SOME RUSTS AND MILDEWS IN INDIA. 



By A. Barclay, M.B., Bengal Medical Service. 



(Plate 298). 



It is somewhat remarkable, considering the economic import- 

 ance of the subject, that no systematic study of the Rusts and 

 Mildews of our cereal crops in India has ever been undertaken. 

 The following notes on some of these may therefore be of interest ; 

 for although this paper contains nothing absolutely new to science, 

 an accurate record of the occurrence of these fungi in India must 

 be interesting to the student of geographical distribution, and to 

 scientific agriculturists. 



In a recent paper submitted to the Asiatic Society of Bengal, I 

 recorded some observations on the prevalence and characters of 

 Rust and Mildew on wheat, and I have therefore excluded this 

 from the present paper. This latter subject is one of the greatest 

 importance ; but our information concerning its life-history is still 

 so meagre and incomplete, that it is premature to enter upon it. I 

 will only note here that, so far as I have been able to gather, the 

 most prevalent form of Rust on wheat, barley, and oats in India is 

 Puccinia Eubigo-vera DC, and not P. graminis Pers. And this is 

 true even of the outer Himalayan region, where Rust is very pre- 

 valent, and where three species of barberry are common (B. 

 Lycium Royle, B. aristata DC, B. vulgaris L.), one of which, B. 

 Lycium, bears an iEcidium abundantly. At the same time I have 

 never been able to find an iEcidium on any species of Boragineae in 

 the Himalayan region, and none is known on the plains. Whilst P. 

 Rubigo-vera is apparently by far the commonest Rust in India, 

 P. graminis is not wholly unknown. I have received specimens 

 of P. graminis from Jeypore, about 200 miles in a direct line from 

 the nearest known habitat of barberry ; but I have never seen a 

 specimen on the crops actually in the neighbourhood of ^Ecidium- 

 bearing barberry. These facts are sufficient to show the mystery 

 in which the subject here is involved, aud that it needs much more 

 study before anything useful can be written on it. 



The fungus on Linum (" Ulsee ") is apparently extremely common 

 over large areas of the plains. It is often so closely concurrent 

 with Rust on wheat and barley, that the uredo stage on Linum has 

 often been supposed to be the cause of the Rust on wheat. This 

 supposition, however, cannot be entertained, with our present 

 knowledge, by botanists. The fungus on Linum is probably a 

 complete autoecious species. 



With these few introductory remarks I pass on to a description 

 of the Rusts with which I am acquainted in India, other than 

 those on wheat, barley, and oats. 



Puccinia Sorghi Schw. on Sorghum vulgar e Pers. (" Jowari"). 

 Through the kindness of Mr. J. A. Baines, C.S., 1 obtained 

 some specimens of rusted Sorghum from the Bombay Presidency. 

 Journal of Botany. — Vol. 28. [September, 1890.] s 



