156 



MEMOIRS OF THE XEW YORK BOTANICAL GARDEN 



Similar differences exist in the performance of sets open for 

 the second period. As a rule the periods for the two sets norm- 

 ally opening on any one day are closely coordinated in sequence, 

 especially for A varieties. But in the B varieties the sets of 

 second-period flowers are rather uniform throughout as to their 

 hours of shedding pollen, while marked differences exist as to 

 the sets of firsts. Thus, for example, the seconds on Meserve 

 and Trapp (chakt 1) act quite alike but tlieir sets of firsts for 

 the same day behave very different as to time of opening. 



Thus, for some varieties and particularly the A varieties, 

 there is normally a short period of overlap or a time when one 

 set is closing and another set is opening. A period of overlaid 

 (for a reverse order of sequence) exists for some of the B varie- 

 ties but for several of these. Pollock, Hardee, Trapp, Estelle, 

 and Taft's Golden, there is normally no overlap but a decided 

 lapse between openings. After the set of seconds which is open 

 in the forenoon is fully closed, there is a period of as long as 

 three hours before the day's set of firsts starts to open during 

 which no flowers are open. Nirody (1922) observed and reported 

 this condition for the varieties Fuerte, Linda, Pollock, Queen, 

 Trapp, and McDonald, and for all but the last named he noted 

 that the flowers Avhich open late in the afternoon are from "fresh 

 buds" and that they close for the night without shedding pollen. 

 Evidently Xirody considered that this was merely a closing for 

 the night, which in these varieties is indeed the case. In none 

 of the A varieties did he discover the closing of sets of first- 

 period flowers at midday and he considered that for these the 

 same flowers were open throughout the day for only one con- 

 tinuous opening. 



In the various charts (1 to 4) the records are arranged with 

 the varieties listed in order according to the time when the first- 

 period flowers start to open. This arrangement brings out the 

 differences that exist among varieties as to the precise time in 

 the same day when the two sets are open, and as to the extent 

 and the particular time of the period of overlap and of the period 

 of lapse between sets. 



A comparison of the charts for different days shows clearly 

 that these relative differences are rather constant characteristics 



