Female and male trees

[mel turner]

In article <4bsamn$j3d at cloner3.netcom.com> d_micro at ix.netcom.com(Michael L Roginsky ) writes:

>>>>Don't forget to include pear and apple trees. Some species require
>cross polination to bear fruit. Othewise all you get is flowers and
>later firewood as you get smart and cut them down...personal
>experience!

I think that these are more likely examples of self-incompatability, & not 
true dioecy -- i.e., they may be plants with bisexual flowers that can only 
fertilize one another, and don't successfully set seed with their own pollen, 
but all do form both pollen and seeds  [there are also a  lot of other 
variations in plant breeding systems out there, including some where plants 
with superficially bisexual flowers are functionally male or female,  species 
with both unisexual and bisexual individuals, etc.]
mdt