UREDINES. 55 



been imagined by botanists who have observed 

 the two separately. These fungi are called 

 tiredineSy the plural of uredo, which is a term 

 derived from the Latin word uro, to burn, 

 because the discoloration of the parts of 

 plants affected by them produces a burnt ap- 

 pearance. The uredines are chiefly found on 

 the young or old leaves of corn-plants, and 

 occasionally on the stems ; but, in the last in- 

 stance, it has been surmised that the indica- 

 tions similar to uredo are only immature forms 

 of puccinia. We shall soon have to advert to 

 this point. There is no stage of growth in 

 which the wheat-plant is free from the attacks 

 of a uredo. Early in the spring it is found on 

 the young blades ; and this year (1846) it was 

 in such quantities in some districts, that the 

 fields looked quite yellow with it, and at one 

 time it produced much alarm. Later in the 

 season, it often abounds in the glumes and 

 paleae of the ear, even after the grain is 

 formed. These yellow or orange uredines are 

 of two kinds. One of them, from the oblong 

 form of its spores, is called uredo linearis, the 

 other uredo rubigOy whose spores are nearly 

 spherical. TJredo rubigo means red rust, and 

 no name could possibly convey a truer idea of 



