Introduction
The Cucurbitaceae is a family of herbaceous and woody vines
concentrated in tropical regions of the world, and much
appreciated for their edible and useful fruits (cucumbers,
squashes, melons, and gourds). While the economically
important members of the Cucurbitaceae have received much
attention by botanists, those wild genera not historically
domesticated by humans are also worthy of study.
Gurania (also known as the "Jungle Cucumber") is one of the largest
genera in the Cucurbitaceae, with an estimated 40-75 species
growing throughout the New World tropics. Gurania flowers
are showy, with an orange to red calyx (sepals)-- a character
not found elsewhere in the Cucurbitaceae. The petals are
tiny, yellow, and mostly hidden by the large sepals, which
attract the hummingbirds and Heliconius butterflies that
pollinate the flowers. Gurania plants are monoecious, meaning
that flowers are only of one sex, but both male and female
flowers can be produced on a single plant. However, they are
not both produced on one plant at the same time, so
plant-to-plant movement by pollinators is neccessary for
fertilization. The green, pickle-sized fruits of Gurania are
known to be dispersed by bats in the genus Phyllostomus, and
are probably eaten by several bird species as well.
Current experts in the Cucurbitaceae, not to mention non-specialists,
find Gurania species notoriously difficult to identify with
certainty. But these showy and ecologically important plants
are found in nearly all moist lowland and montane forests in
the Neotropics, and researchers conducting floristic and
ecological studies in these regions need to identify the plant
species they encounter. No single publication contains keys
and descriptions for all the species of Gurania. Such a
publication, known as a monograph, is the goal of my doctoral
research at the New York Botanical Garden.
During two months of field research on Gurania at the Los Amigos
Biological Station in Madre de Dios, Peru, I was fortunate to
be able to find and study five species of Gurania, growing and
reproducing sympatrically (in one area and simultaneously).
Previously, only two common Gurania species had been
identified in the Los Amigos Conservation Area. Three more
species of restricted habitats were discovered at the station
in the course of my study.
With the assistance of the staff of the Amazon Conservation
Association (ACA) and the Asociación para la
Conservación de la Cuenca Amazónica (ACCA) at
Los Amigos Station, and with laboratory equipment available at
the station's botanical laboratory, I have come to know these
five
Gurania species intimately. Through weeks of pollination
activity observation, habitat investigation, macro- and
micro-photography, and collection of preserved plant samples
for herbarium study, I have accumulated a great deal of data.
This work has also given me a greater understanding of the
characteristics that both demonstrate directional selection
(driving the evolution and divergence of species) and define
the differences between species (allowing me to create useful
keys and descriptions so that non-specialists can identify
these plants). This was an excellent place to gain experience
with Gurania that I can put to use in the herbarium and in
future fieldwork at other sites. This ongoing study was
conducted in collaboration with the
Botany of the Los Amigos
Conservation Area project.