Economy.

If they are pollinated the first day, they do not need to remain open.

It uses up a lot more of the plant's energy to keep the flowers open for
several days.

Most nocturnal flowers are not designed to withstand the mid-day heat.


"Rev "Fragile Warrior"" wrote in message
...
I was just mourning the fact that the beautiful red blossoms on my Passion
Flower vine only live a single day same as the Daylilies that I love so
much. But now I'm wondering why? Does anyone know the biological
explanation for why some flowers bloom for days and days and others only
bloom one turning of the sun? Not to mention the kinds of flowers that
only bloom a single night.

I would think a longer blooming cycle enhances the possibility of
fertilization so there must be some good reason why the flower's bloom
cycle is so short. I even understand why tropical flowers bloom at night
(because insects and breezes and animals are more likely to be out at
night in the tropics, right?) but the short bloom cycle has me baffled.

Help, please!
Thx,
Giselle