XVI International Botanical Congess

Pollinator limitation is a possible explanation of the observation that flowering plants produce more flowers and ovules than fruits and seeds. Hawkmoth pollinated plants may be especially prone to pollinator limitation as hawkmoth populations vary in time and space. Oenothera macrocarpa exhibits a classical hawkmoth pollination syndrome. The purpose of this study is two-fold, first, to determine which species of hawkmoth pollinate O. macrocarpa through direct and indirect methods and secondly, to determine if O. macrocarpa is pollinator limited. This is being done by comparing the fruit and seed set of plants receiving supplemental pollination to that of plants receiving natural pollination. Preliminary data indicate that O. macrocarpa does not have 100% seed set (mean=29.88% ± 19.36 SD). Further results will be presented and discussed.