ON DAHLIAS 155 



species Variabilis y with purple or red flowers ; Coccinea, 

 with scarlet flowers ; and Merckii, with lilac and yellow 

 flowers, are the principal parents of the modern double 

 Dahlias. The Cactus class came, however, mainly from 

 Juarezii, a scarlet species with rolled and pointed florets, 

 which was introduced in 1872. Variabilis was first called 

 Superflua by botanists, not because they wished to place 

 a stigma upon it by conveying that it was superfluous, 

 but to indicate its kinship with the Linnaean section of 

 " composite " flowers, in which the central and outer 

 florets differ. " Variabilis " is in allusion to the variable 

 colour of the flowers. 



The species are not often seen now, but any one 

 interested in them may make some sort of acquaintance 

 with them, either through a botanical garden or through 

 illustrations. Coccinea is figured in the Botanical 

 Magazine, t. 762 ; and Merckii in the same work, t. 3878. 

 Coloured plates such as these have an interest for those 

 who like to compare the old forms of popular flowers 

 with modern ones. Probably no plant has suffered 

 more through the duplication of names than the Dahlia. 

 As we have seen, two generic names were given, and 

 there are many synonyms of the principal species. 

 Variabilis has at least four, and Coccinea three. How- 

 ever, as none is of any garden importance, we need 

 not worry about that, but confine our study to the 

 distinctiveness of the garden varieties. 



Dahlias as Hardy Plants. The Dahlia is not hardy 

 in Great Britain. When we learn that its native country 

 is Mexico, we do not expect it to be able to withstand 

 the winters in latitudes so much farther north. It is true 

 that it is sometimes treated as a hardy herbaceous per- 

 ennial that is, planted out, left to die down in autumn, 

 pass the winter in the open ground, and spring up again 



