Format: ORAL

Rachel B. Spigler

Temple University, Philadelphia, PA, USA

Angiosperms display a brilliant diversity of floral forms, with striking variation in color, size, and scent, and morphology, includingelaborate or specialized structures offering protection or rewards. Floral longevity, the length of time a flower remains open and functional, shows similarly impressive variation across species, ranging from a day or less to over a month, but by comparison has been largely overlooked. Consequently, even though floral longevity should strongly influence fitness by setting a critical time limit on opportunities for each flower to export and receive pollen, we lack a firm understanding of the forces that shape, maintain, and constrain variation in floral longevity. In fact, we even lack basic studies on the heritability of this trait in wild species.Sabatia angularis(Gentianaceae) is a mixed-mating biennial with remarkable intraspecific variation in maximum floral longevity, ranging from plants that produce flowers lasting only 5 days to those with flowers that can last over 20 days within a single population. I will present data from a combination of field and greenhouse studies that characterize factors maintaining or constraining this variation, highlighting the importance of heritability, trade-offs, functional and ecological constraints, and plasticity.