192 



MEMOIRS OF THE XEW YORK BOTAXIC.VL GARDEN 



EXPLANATION OF CHART 5 



Different types of flowering cycles for avocado flowers are here shown 

 diagramatically. The different conditions through which sets of flowers 

 pass are traced for a period of sixty hours. This shows the complete cycle 

 for at least one set and for such other set or sets as may be in action 

 during this time. 



The first or female anthesis is indicated by the continuous line begin- 

 ning at a bar. Dashes and dots indicate the second o]jening. The in- 

 terval between the two periods of opening is shown by the letter c. The 

 entire cycle of flower action extends from the bar to the x. Sets con- 

 tinuing from previous days or continuing later than the close of the 60 

 hour period of the chart are indicated by the arrows. 



The cycle of dianthesis typical of A varieties normally covers about 36 

 hours. It begins in the early forenoon and ends in the late afternoon of 

 the following day. The female and the male openings are separated by 

 an interval of about 24 hours during which the flowers are closed. The 

 sequence of sets each with this behavior brings two different sets into 

 bloom each day. 



Normally all B varieties have flowers in the second or male anthesis 

 open during the forenoon and flowers of the first or female opening open 

 in the afternoon. The cycle typical of different varieties may, however, 

 be quite different. For some (see B 1) the cycle covers only 2-1 hours or 

 less and only one set is in action at a time. For others (see B 2) the 

 cycle of sets extends over 48 hours. The inten-al between the develop- 

 ment of the pistil and the maturity of the stamens covers about 24 hours. 

 For certain varieties a single set of flowers may, at least under certain 

 conditions, divide into two groups of flowers as shown at B 3. One group 

 completes the cycle in 24 hours and the other completes it in 48 hours. 



All the different types of flowering cycles here shown may exist when 

 the daily alternation of all the varieties is quite normal. Under ab- 

 normal and off -stride blooming the cycles of sets are, of course, also very 

 irregailar. 



