Rice, Stanley A. , Rice, A. Lisette .
Male cottonwoods open their flowers earlier than female cottonwoods.
BUDBURST dates for 276 cottonwood (Populus deltoides) trees at two latitudes (34° and 36° N) were determined. Trees were chosen before budburst, eliminating bias in choice of male and female trees. There were 159 male and 117 female cottonwood trees in the sample. On the average, male cottonwood trees at both latitudes burst their buds 5.26 days after the first budburst at that latitude, while female cottonwood trees at both latitudes burst their buds 8.85 days after the first budburst at that latitude. Due to sequential opening of flowers within an inflorescence, pollination probably continued at least a week after budburst. The range of budburst dates was about 18 days at each location. One possible interpretation of these results is sexual selection; in male cottonwoods, competition may take the form of earlier budburst. A significant interaction factor between gender and location effects on budburst date indicates that males did not open earlier than females in every location at 34° N latitude. -DU
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1 - Southeastern Oklahoma State University, Biological Sciences, Box 4027, Durant, Oklahoma, 74701, USA
2 - 7324 S. Trenton Ave., Tulsa, Oklahoma, 74701, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Wednesday, August 2nd, 2006
Time: 8:00 AM