177 



variety is, in reality, one plant whose parts have been separated 

 and grown in different localities. Thus the standard of the variety 

 is assured for the method of its propagation does not involve the 

 variation that is sure to come when there is the seed propagation 

 of hybrids. 



It will readily be understood how an entire clonal variety may 

 be self-fruitless. When the original seedling plant happens to be 

 self-incompatible and unable to set fruit and seeds to its own 

 pollen all the plants obtained by dividing its roots and stems are 

 necessarily self-sterile and also pollinations between them are no 

 more effective than are pollinations from flower to flower on any 

 one of the plants as grown. And so many of the clonal varieties 



Figure 3. Here is shown (on opposite page) the range in the size of 

 the flowers in the various hybrid clay lilies recently produced at The New 

 York Botanical Garden. Some suggestion of the coloring is given by the 

 shading. All are rather " full " flowers and are among the best of the 

 seedlings selected for propagation. 



A rather small flower of the darkest shade of red yet seen in any day 

 lily is shown at the upper left. The flower standing uppermost has a most 

 delicate coloring and is to some persons the first choice of all the seed- 

 lings. Below it and to the right is a flower with colors somewhat as in 

 H. aurantiaca and just below this is a full flower with waxy sheen and a 

 clear light yellow. At the extreme left is a somewhat trumpet-shaped 

 flower of good size and of a pleasing orange color, tinged with a faint 

 halo of red. In the center is the same large flower shown in Figure 2. 



Seven different species and varieties were involved in the parentage and 

 grandparents of this group of hybrids. 



of the day lilies are self-fruitless throughout, as were the orig- 

 inal seedlings. Certain varieties are, however, more or less self- 

 fruitful. In Hemerocallis cross-incompatibilities between seed- 

 lings of the same species, or between members of a set of hybrids 

 are also very general and so the clonal varieties developed from 

 them are cross-sterile. Hence failures to set seed to many polli- 

 nations both self and cross are very frequent and persistent in 

 the day lilies which one may grow. 



All the species of Hemerocallis in the trade are propagated 

 vegetatively. There are therefore clonal strains in all the so-called 

 species in cultivation. The old familiar fitlva has been propa- 

 gated exclusively as a clonal variety for at least 500 years. Ap- 

 parently all the plants of it now growing or ever grown in Europe 

 and America are merely parts of one plant ! Some study will be 



