194 



MEMOIKS OF THE NEW YORK BOTANICAL GARDEN 



EXPLANATION OP CHART 6 



A drop in temperature on IMareh 3rd to a maximum of 77° and a 

 minimum of 46° (about 10° lower than the maximum and the minimum 

 of the previous days) gave the irregular behavior in flower opening 

 recorded in this chart. 



On the 4th, the varieties which normally open firsts in the forenoon 

 (Group A) went through their daily sequence quite normally and quickly 

 with only a delay of about an hour in starting compared with the record 

 of the i^revious week. The varieties heading the list of the afternoon 

 first-openers were also near normal stride, but Hardee, Winslowson, Pol- 

 lock, Estelle, Trapp, and Taft's Golden, produced a set of single-opening 

 flowers (indicated by -i-) which had entirely skipped the first-opening 

 on the 3rd. These flowers shed pollen feebly and those of Ti'app shed no 

 pollen at all. Fuerte and Harmon had a set in first-opening continued 

 from the preceding day for a time in the morning, so these varieties had 

 three different sets open during the day. Estelle and Taft's Golden pro- 

 duced no first-period flowers and Trapp only a few up to the hour of the 

 last observation at 8:00 P. M. 



"With the rising temperature of the afternoon of the 4th and the night 

 following, the flower behavior on the 5th was more nearly normal with a 

 noticeable shift to earlier hours of the day. On Trapp nearly all of the 

 flowers shedding pollen were flowers of a single opening and all those for 

 Estelle were evidently of this type of opening. For this day the set of 

 firsts for Trapp and Estelle started opening shortly after 7 :00 P. M. 

 which was after dark. 



For only a few varieties and for a short time only (see where dots 

 overlap the continuous line) was there an opportunity for close-iDollina- 

 tion. 



