Figure #4 Timing of avocado flowering
The avocado is also unusual in that the timing of the male and female phases differs among varieties. There are two flowering types, referred to as "A" and "B" flower types. "A" varieties open as female on the morning of the first day. The flower closes in late morning or early afternoon. The flower will remain closed until the afternoon of the second day when it opens as male. "B" varieties open as female on the afternoon of the first day, close in late afternoon and re-open in the male phase the following morning. See Figure 4 for a diagrammatic representation.