Efects of florivory on the anatomy, histochemistry and resource
production of lowers of Senna aversiflora (Herb.) H.S.Irwin & Barneby
Abstract
Florivory directly affects floral structures, especially petals and
anthers. The physical damage to these whorls can alter the
characteristics of the flowers, compromise their functions and,
consequently, impact fertility and reduce the reproductive success of
the species. We provide the floral anatomical description of Senna
aversiflora (Herb.) H.S.Irwin & Barneby. We measured various
anatomical traits of petals and quantified the levels of chemical
compounds and the pollen produced by intact and damaged flowers in order
to identify characters associated with the plant-florivore interaction.
We found that the epidermis (adaxial and abaxial surfaces) and mesophyll
of the petals of healthy flowers was thicker when compared to damaged
flowers. We infer that the smaller thickness of traits associated with
the absence of characters with deterrent effect on herbivores and
greater production of attractive/nutritive chemical compounds in
relation to defense compounds contribute to make the species highly
susceptible to florivory. Pollen production in damaged flowers did not
differ between the different stages of floral development. However,
florivory has a negative effect on the amount of pollen produced.
Damaged flowers had less pollen than healthy flowers. We conclude that
florivory in S. aversiflora exerts significant pressure on petal
anatomy and resource production by flowers.