PROLIFICATION IN A 



DOUBLE- FLOWERED FORM OF 



CALENDULA OFFICINALIS 



Extremely Rare Development of Multiple Buds in Pot Marigold 



Peter Bisset 

 Plant Introducer, U. S. Dspartmsnt of Agriculture. 



PROLIFICATION is a word often 

 used by horticulturists to denote 

 a departure from the ordinary 

 method of flowering of cultivated 

 plants. It is used generally where 

 more flower buds are produced than 

 is commonly the rule, and especially 

 so when they appear where ordinarily 

 they would not, as in the present in- 

 stance, where a number of flower buds 

 were developed from one normal flower 

 head. 



Although prolification is not un- 

 common in some double-flowered 

 plants, the writer has never before 

 seen this occurrence in the Calendula. 

 These plants were grown in' the 

 spring of 1918, at Twin Oaks, Wash- 

 ington, D. C, by Mr. E. G. Anderson, 

 who is superintendent for Mr. Charles 

 J. Bell. My attention was attracted to 

 the strange behavior of several of the 

 flowers ; the central flower was appar- 

 ently normal, but before it was fully 

 developed several buds were pro- 

 duced — some from the center of the 

 flower (see Fig. 12). These devel- 

 oped into flowers and opened fully, 

 although not as large as the first ; these 

 later, in several instances again pro- 

 duced buds that developed flowers, they, 

 in turn, not as large as the second 

 tier (Fig. 13). 



I left at about this time for the 



West and therefore did not see the 

 final stages of these flowers, but asked 

 Mr. Anderson to save any seed that 

 might mature so that we could try 

 another experiment to determine if 

 this prolification would become fixed. 

 Unfortunately no seed developed, and 

 the plants, being annuals, were neces- 

 sarily lost. 



This form of prolification often oc- 

 curs in the double-flowered English 

 daisy, and in England has received the 

 common and expressive name of the 

 Hen-and-Chicken Daisy. Prolification 

 also frequently occurs among our 

 common roses. In the rose, however, 

 it often takes the form of the pro- 

 longed flower stalk coming up from the 

 center of the parent flower, often pro- 

 ducing leaves and then a bud which 

 develops later into a flower. 



The Calendula plants, here shown, 

 were grown in a greenhouse bench in 

 rather rich soil and where they were 

 given the best of care as regards water- 

 ing, temperature, fertilization, etc. — in 

 fact, ideal conditions for the best de- 

 velopment of normal flowers. It might 

 be asked, were the conditions conducive 

 to the production of such prolified 

 flowers as were borne by several of 

 the plants. I am inclined to think 

 that this was the case, and that they 

 were over-stimulated. 



323 



