FLORIDA STATE HORTICULTURAL SOCIETY 



85 



available for study, or where observations 

 were made on only one day. In some of 

 these cases the identity of a tree may be 

 in error as seems to be the case of a single 

 tree called El Oro, which was studied in 

 California in 1923. 



The variety Collinson appears to be 

 completely sterile as a pollen parent. The 

 flowers have two periods of opening. The 

 second-period flowers open in the after- 

 noon but the anthers remain closed and 

 no pollen is shed. Observations have been 

 made of the flowers on the original tree 

 of Collinson, on some of the first trees 

 propagated from its buds and on about 

 thirty others of blooming age in grove 

 plantings. On some of these, observa- 

 tions were continued day after day over 

 a period of more than two weeks. In 

 two instances a single anther valve was 

 found lifted but no pollen was found. 

 An examination of the flowers closed af- 

 ter the second opening shows that the an- 

 thers had shed no pollen after the final 

 closing. This variety appears to be com- 

 pletely impotent as a pollen parent. It 

 sheds no pollen for any sort of pollination. 

 Fruits maturing on it are the results of 

 cross-pollination. 



A glance over the various charts shows 

 a noticeable difference between the differ- 

 ent varieties as to the hours of a single 

 day when the two sets of flowers areopen. 

 Thus for the varieties studied on Febru- 

 ary 24th, there was a difference of two 

 hours between the time when firsts opened 

 on Perfecto and the time when the set of 

 firsts started to open on Pinelli. A still 

 greater difference is seen in the time when 

 firsts started to open in the afternoon. 

 There are also variations in the time when 



seconds were open and for the period 

 when they shed pollen, but this is more 

 nearly the same for the various varieties 

 of a group (A or B) than is the period 

 of the opening of the firsts. These rel- 

 ative differences continue day after day. 

 Atlixco and Perfecto open their first-pe- 

 riod flowers early, Taft and Wagner late. 



For the varieties in Group B, Meserve 

 and Panchoy have firsts relatively early 

 in the afternoon in comparison with Pol 

 lock, Trapp, Estelle and Taft's Golden. 

 For the varieties opening firsts late in the 

 afternoon there is, under normal condi- 

 tions, a distinct period of one or more 

 hours between the time when second-pe- 

 riod flowers are fully closed and the time 

 when the firsts begin to open. It is to be 

 noted that none of these late-opening va- 

 rieties of the B group were available for 

 study in California so the records of flow- 

 er behavior obtained there show less vari- 

 ation among varieties. 



The observations both in California and 

 Florida indicate that the varieties of the 

 B class exhibit the greatest irregularity 

 and off-stride behavior under unfavorable 

 weather conditions. Weather which mere- 

 ly delays the opening of the two sets in 

 varieties of the A group will often cause 

 various varieties of the B group to con- 

 tinue a set of firsts open over night and 

 into the next day, or to skip the set of 

 firsts, or to have them open for a period 

 during the night. The second opening 

 of a set, or part of a set, may be delayed 

 until the second day giving an interval of 

 about thirty-six hours between the closing 

 of firsts and the opening of seconds. For 

 some varieties this interval of thirty-six 



