4F2 THE FUNGUS PESTS OF CERTAIN FLOWERS 



FUNGUS OF HOLLYHOCK DISEASE 

 Puccinia mah>acearum 



of the white variety of the Musk Mallow (Malva moschatd] 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 Australia, and then 

 reached England by the con- 

 tinent of Europe. Great fears 

 have been entertained of this 

 fungus attacking the Cotton 

 plant, as the Cotton plant be- 

 longs to the same family as 

 the Hollyhock. 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 required. 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 centre. 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 corn fields (P. Rh&as\ and it badly attacks 



