196 



MEMOIKS OF THE NEW YORK BOTANICAL GARDEN 



EXPLANATION OF CHART 7 



These records for February 12 and 13 show some ol' the most extreme 

 ot¥-stride behavior observed in Florida during the season of 1925. The 

 weather during tlie 9th and 10th was warm with maximum tempera- 

 tures of 84° and 91°. On these days the records of flower behavior were 

 almost identical with that of February 24, shown in chart 1. Heavy 

 rain on the night preceding the 11th and a shower on that afternoon were 

 followed by clear colder weather and strong northerly winds. The maxi- 

 mum day temperatures were 64° on the 12th and 69° on the 13th and 

 on the night preceding the 13th there was the onl.y frost experienced 

 during the months of February and J\lareh in the orchards where the 

 observations were made. 



The openings of both first-period and second-period tlowers were de- 

 layed or even omitted and when they did open the closing was delayed 

 so that in most cases the set or sets open in the afternoon continued thus 

 over night (as shown by the arrows) and most of the following day. On 

 the 12th, only one set of flov/ers opened for most varieties ; in the A group 

 the set of first-period flowers opened late and except for Solano remained 

 open all night and into the next day. The second-period set for the B 

 varieties also opened late and remained semi-open all night, becoming 

 more open the following day and shedding pollen and closing at the hours 

 indicated. 



The two sets of flowers, which in favorable weather would have opened 

 and closed on the 12th, took two days for opening. The first-period set 

 for each of the B group was delayed 24 hours. The two sets which in the 

 normal sequence would have opened on the 13th were delayed in opening 

 until a later date. 



During much of this time flowers of both sets were only semi-open 

 with feeble and incomplete action of flower parts, and slow, irregular and 

 incomplete shedding of pollen. There was on the 13th a period when the 

 first-period floweis overlapped pollen shedding for Atlixco, Grande, 

 Wagner, Fuerte, Harmon, Winslowson, and Pollock. During such flower- 

 behavior there is, it would seem, chances for self-pollination but the ex- 

 tent to Avhich flowers in such otf-stride bloom can function is not yet 

 determined. 



