The Fungus Pests of certain Flowers 



to the Hollyhock, for it attacks many malvaceous plants, notably 

 the Mallows of our hedgesides. We have seen plants of the white 

 variety of the Musk Mallow (Malva moschata) totally destroyed by 

 this parasite. The home of the Hollyhock fungus is Chili, whence 

 the Potato fungus reached us. The Hollyhock fungus first attacked 

 the malvaceous plants of Aus- 

 tralia, and then reached Eng- 

 land in 1873 by the continent 

 of Europe. The best and 

 cleanest seeds of the Holly- 

 hock should be purchased. 



A fragment of a Hollyhock 

 leaf is illustrated at A, dotted 

 with the characteristic black 

 pustules ; these pustules cover 

 the stems as well as the leaves. 

 At B is shown the edge of a 

 pustule enlarged one hundred 

 diameters and seen in section ; 

 to show the whole of a pustule 

 in section from six inches to 

 a foot of space would be re- 

 quired. Bursting through the skin of the plant may be seen a dense 

 forest of threads, each thread bearing a spore with a joint across the 

 middle. One pustule alone will produce thousands of these double 

 spores. At C some of the threads and spores are still further 

 enlarged to two hundred diameters, and at D one ripe spore is shown 

 falling from the thread and breaking asunder each piece is a 

 reproductive body or spore. When mature, these minute blackish 

 spores or ' seeds ' are carried in the air by millions. At E one of the 

 compound spores is enlarged to four hundred diameters. As this- 

 disease is seated within the tissues of the plant, remedies are difficult 

 of application, and in many cases all attempts at cure have failed. 

 No doubt the fungus is nursed by malvaceous weeds. Infected 

 Hollyhock plants and allied weeds should be destroyed by fire or by 

 deep burying. 



Poppy Disease. Garden Poppies are often attacked by a fungus 

 pest closely allied to the fungus of the Potato disease, and named 

 Peronospora arborescens. It grows sometimes in abundance on the 

 common Red Poppy of cornfields (Papaver Rhaas\ and it badly 



43 1 



FUNGUS OF HOLLYHOCK DISEASE 

 Pnccinia malvacearum 



