On Jan 29, 2012, at 11:29 PM, The Silent Seed <santoury@aol.com> wrote: > > This is the first time I've ever heard of an actual species (of anything) being sterile beyond artificial damage, such as neutering, or radioactive exposure, etc? There are numerous cases of sterile species in the plant world. In the case of garden ornamentals it's often the case of asexual propagation over many years, selection of better growing plants ( sometimes the result of polyploidy) erc etc. There are several food crop plants that are sterile. For instance the common edible ginger (z officinale) is completely sterile ( until recent lab work was done to create seed bearing plants). This is a result of asexual propagation over thousands of years. Turmeric and many related curcuma spp are sterile due to polyploid issues. Many plants that make bulbils or plantlets or just spread like weeds have lost the need to produce seed. The asexual propagation is so much faster and more efficient. This can happen without mans interference. In the case of cultivated plants you can also have plants that are self incompatible as well incompatible with other species. This gives the false impression of sterility, when it would be fertile with a different clone of the same species. Tim Chapman