KAY, ELMA E.* and PETER BERNHARDT. Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103. - Evolution of vertebrate pollination in Passiflora sp. of the Greater Antilles.
The Greater Antilles is home to a group of passionflowers in three
subgenera of the genus Passiflora (Passifloraceae), which are
primarily hummingbird-pollinated. Most of the species in this group
have red, tubular, odorless flowers with diurnal anthesis. In
contrast, the pendulous, lime-green flowers of P. penduliflora,
found only in Cuba and Jamaica, emit a musty smell at night and are
pollinated by the glossophagine bat, Monophyllus redmani. The
separation of the group into different subgenera was based mainly on
floral characters related to pollination, including the type of
corona. This structure is usually composed of separate filaments
protecting the entrance to the nectar chamber. However, in some
species in the Greater Antilles, the individual filaments have fused
into a tube. The first objective of the study was to gather detailed
information on the pollination ecology of species representative of
the three Greater Antillean, vertebrate-pollinated subgenera,
including data on the foraging behavior of floral visitors, and
phenology, breeding system and rates of nectar secretion of the
passionflowers. The second objective was to generate a phylogenetic
hypothesis of the relationships among the species in the three
vertebrate-pollinated subgenera of the Greater Antilles. This
hypothesis was used to map individual characters that are ecologically
important in the pollination of Passiflora sp.. Differences in
floral structures such as the corona appear to play an important
ecological role in specialization to certain pollinators and may have
been important in driving the evolution of different breeding systems
in vertebrate-pollinated Greater Antillean Passiflora.
Key words: bat-pollination, Greater Antilles, hummingbird-pollination, Passiflora