A Disease of Hollyhocks. 



The hardy hollyhock has few enemies, yet there is one, the mallow 

 rust, to which it occasionally falls an easy prey. This is a malady 

 common to a number of related species, among which the hollyhocks 

 are the worst sufferers. When in its grip, with leaves drooping and 

 yellow, putting forth blossoms in a half-hearted manner or not at all, 

 they are no longer 



" Queen Hollyhocks, . 

 With butterflies for crowns" ; 



their tall and ragged forms, no longer courted by insects, become 

 reminiscent rather of the other end of the social scale. Covered with 



pustules, they fail, and are 

 cut down, leaving blank 

 the air that was formerly 

 alive with their high aspira- 

 tions. 



The cause of this catas- 

 trophe is a fungus whose 

 attacks are more easily 

 located than is often the case. 

 The diseased spots form 

 very striking objects on 

 the leaves and stems of the 

 plants. Dark-brown warts 

 of considerable size are to 

 be seen in hundreds. Even 

 the greener parts of the 



in or near most flower gardens. The dark raised warts disease Spreads with great 

 or pustules are the most obvious signs of the disease. They .,. ,\. , ,, ' -, 



occur on the leaves, stalks, and fruits. rapidity it the weather and 



location are favourable, and 



an apparently sound plant may succumb in a few days' time. As the 

 warts increase in size, and begin to take on their final dark-brown 

 colour, the leaves of the Hollyhock lose their normal greenness, and 

 assume various shades of yellow and brown. Later they dry up com- 

 pletely in the worst cases. 



If we examine the full-grown warts we find them composed of 

 immense numbers of spores of the form shown on the following 

 page. These when they germinate, which they readily do in 

 water in our cultures, or in dew on the surface of plants, or in any 

 moist situation, appear as in Fig. 110, the small dark and pear-shaped 

 sporules being those that are capable of again infecting the hollyhock 

 or any one of a number of its congeners, such as the common door- 

 yard weed, the Wild Mallow. 



As a leaf of the hollyhock often bears several hundred warts, and 

 each wart contains several hundred spores, each of which, if it secures 

 a proper chance, will produce ten or twelve sporules, we need not 

 wonder that this disease sometimes becomes quite a scourge. 



