Scott Shumway asked:
>If dioecious plants have male and female flowers on separate plants and
>monoecious plants have male and female flowers on the same plants, then are
>plants with perfect flowers also considered to be monoecious? My
>impression is that the answer is "no", but I have never been able to figure
>out WHY. Can someone straighten me out? Thank you.
The terms monoecious (one household) and dioecious (two households) are
applied ONLY to plants that have unisexual flowers. The terms normally are
not applied to plants with bisexual flowers. I think the reason for this
conventional use of more restricted meanings for the terms is due to the
wide variety of compatability mechanisms found in plants. Plants which
have bisexual flowers capable of being pollinated from flowers of the same
plant are sometimes called "functionally monoecious" while those plants
with bisexual flowers that require pollen from another plant are sometimes
called, "functionally dioecious." My experience, however, is that you are
less likely to confuse your students if you stick with using the terms
monoecious and dioecious only with unisexual flowers, i.e., strictly with
morphological differences and not try to use the terms to describe
compatibility/
incompatibility mechanisms which often are chemical rather than morphological.
Dr. David W. Kramer
Department of Plant Biology
Ohio State University at Mansfield
1680 University Drive
Mansfield, OH 44906
(419) 755-4344 FAX: (419) 755-4367
e-mail: kramer.8 at osu.edu
