Choosing the sex of your tree
A red maple has what are called "differentiated" flowers: some are male, bearing only stamens (Male flower organ bearing the pollen.), and others are female, having only pistils (Female structure of the flower.). A tree with stamens and pistils in separate flowers is called monoecious (Qualifies a flowering plant whose people are both male and female.). But not all trees are like this.
A white ash practises "segregation of the sexes", separating its male and female populations. This tree's flowers are either all female or all male, never both; it is dioecious. A black ash, however, is sometimes dioecious and sometimes monoecious. Talk about complicated!
© Jardin botanique de Montréal (Robert Mineau)
A tree with only male flowers will never produce fruit. It can invest the energy it saves in its growth and in producing pollen. This can be useful in landscaping, as the fruit of some trees just plain stinks! If you want to avoid the problem, plant only male trees.