Reproductive Effort and Output in Atypical Morphotypes of Mountain Purple Pitcher Plant, Sarracenia purpurea var. montana Schnell & Determan

Michelle Paredes

mparedes@unca.edu

BIOLOGY

In 2022, an unusual population of the carnivorous Mountain Purple Pitcher Plant, Sarracenia purpurea var. montana, was observed in western North Carolina. This population included some individuals exhibiting floral characteristics not typically observed in other Sarracenia, including duplicate petal and sepal whorls and an upward floral orientation. Atypical floral traits can lead to negative consequences, including increased energy expenditure to floral tissue, deterrence of pollinators, and susceptibility to pollen damage. The objective of this study was to investigate relationships between these flower features and reproductive success. To achieve this, we selected flowers from 73 plant clumps and observed them over a nine-week period during the summer of 2023. We identified the number of flowers per clump, floral orientation, and number of petal and sepal whorls. We collected anthers to quantify pollen viability and gathered mature flowers in early fall to count seeds. Χ2 tests revealed significant associations between sepal and petal characteristics. Wilcoxon tests highlighted that clumps with duplicate sepal morphologies yielded more flowers per clump. Among the floral components, flowers with duplicate petals had more viable and total pollen production but less inviable pollen. Atypical pedicel orientation was associated with more viable, inviable, and total pollen production. Furthermore, duplicate petals were associated with fewer mature seeds, while duplicate sepals were associated with fewer immature seeds. The co-occurrence of duplicate petals and sepals in individual flowers could suggest shared genetic factors controlling these two floral characteristics. Additionally, pollen production could be influenced by resource allocation going towards duplicate petal whorls or influenced by flower orientation and associated environmental damage. Lastly, the arrangement of flower whorls might influence pollinator interactions, potentially enhancing attraction or affecting the accessibility of the ovary, thereby influencing fertilization. Future research will explore genetic markers that could be responsible for variations in flower orientation and whorl duplication.

Dec-14-2023