Addisonia 57 



(Plate 221) 



DAHLIA "MISS NANNIE B. MOOR" 

 " Miss Nannie B. Moor " Dahlia 



Garden Hybrid 

 Family CarduaciBa:^ Thistle Family 



This Californian dahlia, with its very full and double, rosy 

 lavender-pink flower-heads, is an excellent representative of the so- 

 called "cactus" dahlias. The "cactus" group of dahlias is one of 

 comparatively recent origin and one that has done much to popu- 

 larize dahlias in the last few decades. The general appearance of 

 the flower-heads in this class is so very different from that in the 

 primitive "single" varieties and also from that in old-fashioned 

 ball-shaped double dahlias that many people do not at first sight 

 recognize them as dahlias at all. 



According to the definition framed by the American Dahlia 

 Society, the flower-heads in the "cactus" type must be "fully 

 double," which, however, is not interpreted to mean that they 

 may never show an "open center" or any central florets with 

 tubular corollas, for any "fully double" dahlia is likely to do this 

 with age or on occasion. Being "fully double" simply means that 

 at the climax of the perfection of beauty of the flower-heads as a 

 whole, no "open center" is visible. Under the head of cactus 

 dahlias, two subordinate groups are currently recognized, the "true 

 or fluted type" and the "hybrid cactus type." In the first, the 

 floral rays are long, narrow, straight, incurved, or twisted, "with 

 sharp, divided, or fluted points and with revolute margins, forming, 

 in the outer florets, a more or less perfect tube for more than half 

 the length of the ray." In the hybrid cactus type, the floral rays 

 are comparatively short, "broad, flat, recurved or twisted, not 

 sharply pointed except when tips are divided (staghorn), margins 

 only slightly revolute, and tubes of outer florets, if any, less than 

 half the length of the ray." 



The known history of the "cactus" dahlias apparently begins 

 in the autumn of 1872, when a Dutch horticulurist, J. T. Van der 

 Berg, received from a friend in Mexico a consignment of seeds, 

 bulbs, and roots. Among the mostly rotten bulbs and roots was 

 one dahlia root which was alive and from which slip-grown plants 

 were propagated during the following winter and spring. These 

 plants produced rich crimson flowers of a form very different from 

 that of any dahlias known up to that time. This new species or 



