Hollyhock Fungus
(Puccinia Malvacearum). This fungus is met with on several species of the order Malvaceae, but is particularly hurtful to the Hollyhock. It forms on the lower (seldom on the upper) surface of the leaves small raised spots, at first red-brown, but becoming darker. On the other side of the leaf, the spot is indicated by a discoloured mark. If the attack is severe, the leaves are destroyed, and the plants perish. On microscopic examination, the raised spots are found to be made up of spores of a Puccinia supported on very long hyaline pedicels. These spores are at first covered by the epiderm, but are exposed by bursting through it. This fungus is known only in the Puccinia form; and the spores have been found to germinate almost as soon as mature. The rapid germination explains, probably, the wide and speedy diffusion of the fungus in Europe, in the years 1873 and 1874. It is believed to be a native of Chili, from which country the types of the species were obtained by Montagne. In Europe, it was first observed as dangerous to Hollyhocks in 1873; though specimens were found in Spain as early as 1869. In the former year, it appeared, almost simultaneously, in France and in various places in England; and, in the autumn, in Germany also. Next year, it spread through Germany, Holland, Hungary, and parts of Italy. For a time, it proved most destructive to Hollyhocks; but, as has occurred with other parasitic fungi, its virulence has greatly abated in later years. The best means of treatment is to destroy all leaves as soon as they show signs of being attacked, and to prevent the growth of the other food-plants of the fungus in the neighbourhood of Hollyhocks.