(b) : Puccinia graminis tritici belongs to basidiomycotina and causes black rust of wheat. It is internal obligate parasite. It is found everywhere, where wheat is grown. The teleutospores of the fungus causes the rust. They are produced inside teleutosori. These telia form elongated, dark brown to black pustules on the surface of stems and leaves of the wheat. Albugo candida causes white rust of crucifers. Melampsora lini causes linseed rust. Claviceps purpurea causes ergot of graminae.