Something strange I seemed to notice, Oroblanco blossoms only have 4 petals?

[SoCal2warm]

Something kind of strange (and kind of irrelevant) I seemed to notice.
Oro Blanco grapefruit blossoms seem to almost always have just four petals. But different pomelo varieties I have seen, their blossoms almost always have 5 petals, and it's the same story with every other citrus variety I have seen (including grapefruit of course).
I could be wrong, but is there something special about Oro Blanco? What could be the cause of this strange phenomena and does it have any practical significance?


I also found on Fruitipedia a picture that shows a couple of Ugli Fruit blossoms, all with only 4 petals.

[JJROSS54]

Very Interesting,  I will have to  look at mine the next time it blossoms, but that will most likely be next spring.