(Reprinied from Journal of the Horticultural Society of New York, in 4: 58-78. March 1 1, 1925 



THE CLONAL VARIETY IN HORTICULTURE 



By a. B. Stout, New York Botanical Garden 



NEARLY all the most important fruit crops, certain of the 

 root and tuber crops, and a long list of the perennials famil- 

 iar to the flower garden are propagated exclusively by vegetative 

 means. 



When the propagation is from roots as in the Sweet Potato, 

 from tubers as in the Irish Potato, from the crown of the stem 

 attached to the root as in the Dahlia, from bulbs or bulblets as in 

 the Tiger Lily, from runners as in the Strawberry, or from cut- 

 tings as in the Grape, all the individuals (roots, stem, branches 

 and all) of a variety are merely parts of one original seedling or 

 bud sport. In the case of the propagation of the Apple, Peach, 

 Plum, Cherry, Feijoa, Avocado, Orange, etc. by budding or by 

 grafting the trunks and the branches grown from the inserted buds 

 or scions of any one variety are all sister branches. Thus all the 

 many plants of the Concord Grape are branches derived from one 

 seedling and the tops of all the Baldwin Apple trees grown are 

 the branches of one seedling plant. Except for bud variations 

 that may have arisen in the course of the repeated propagations, all 

 plants of the variety are inherently alike with a constitution that is 

 identical. In a sense, the entire variety is really one plant. Such a 

 variety is known as a clonal variety in distinction from a variety 

 grown exclusively from seeds as is one of the annuals of the field 

 and the flower garden. The distinction is readily evident and it is 

 one of particular significance in regard to certain problems in the 

 propagation, the culture, and the orchard management of crops. 



There are two main advantages in clonal propagation. Usually 

 it gives an easy and a quick means of propagation ; for example it 

 is by far much easier to obtain good plants from the runners of the 

 Strawberry or from cuttings of the Grape than to grow them from 

 seed. But a very important reason for propagating many horti- 

 cultural crops by vegetative means is that the individual plants do 

 not breed true to type from their own seed. 



Undoubtedly hundreds of seedlings of the Concord Grape, of 

 the Bartlett Pear, or of the Baldwin Apple could be grown without 



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