Breeding 63 



are traceable to inbreeding roots which are 

 slender and fibrous, and which unnecessarily 

 dry out quickly. Pendulous flower heads due 

 to weak stems, shy blooming varieties all have 

 related parentage. The European varieties of 

 incurved cactus dahlias have had all these 

 defects, but lately fresh blood has been added 

 and the newer ones are as vigorous and free as 

 any one could wish. When we want to improve 

 the stem, colour, root systems, or any defect in a 

 given variety, we must give it the strength of an 

 entirely different type. Many breeders go back 

 to the original Juarezii or some of the wild 

 dahlias of the mountains. It takes several 

 generations to do this, and men have spent half 

 a lifetime before they have satisfied their ambi- 

 tions. 



Back in Mexico there are species of dahlias 

 which have never been used in breeding. Think 

 what possibilities are hidden in their pollen! 

 In certain parts of Yucatan there are dahlias 

 which are not herbaceous, but grow to be 

 shrubs and even trees. The natives chop off 

 branches and stick them into the ground, and 

 they root as easily as a willow. One of these 

 tree dahlias is called "Imperialis" and now 

 thrives in the warmer parts of our country where 

 there is no frost. It is tall and slender in growth ; 



