Showcase of Undergraduate Research and Creative Endeavors (SOURCE)

Investigation of an Indirect Defense Mechanism of Chapmannia floridana in Florida Scrub

Glandular trichomes (i.e., sticky hairs) that entrap carrion act as indirect defenses in some plant species. The sticky hairs attract predators that consume the carrion. Predators then deter herbivores from harming the plant, leading to an increase in the survival and/or reproduction of the plant. Flowering stems of Chapmannia floridana (Florida Alicia), a perennial plant endemic to Florida, are covered in sticky hairs, which may act as an indirect defense. For 84 flowering C. floridana individuals across six habitats in the Florida scrub ecosystem, we counted the number of fruits, flowers, and buds present and documented any damage to reproductive structures. In addition, we counted the number of carrion, herbivores, and predators on each flowering stem. There was a positive relationship between the length of the trichome-covered portion of the stem and the number of carrion trapped. Only 19% of flower buds, 15% of flowers, and 10% of fruits we counted were damaged. We found predatory spiders on 6% of flowering stems and herbivores such as grasshoppers and caterpillars on 37% of flowering stems. For scrubby flatwoods and firelane habitats, we found no association between habitat and damage. There was no association between carrion presence and damage; however, the probability of damage to reproductive structures decreased as the number of trapped carrion increased. Overall, our results suggest that herbivory of C. floridana reproductive structures is relatively low and that glandular trichomes on C. floridana may be acting as an indirect defense.