Pollination biology ofGeissomeria pubescensNees (Acanthaceae) in a forest remnant in central Brazil

Abstract

Specialized plants like those in genus Geissomeria Lindl. (Acanthaceae) seem to depend directly on pollination by hummingbirds for reproduction. The goal of this study was to investigate the pollination biology of Geissomeria pubescens Nees (Acanthaceae) in a forest fragment in the municipality of Catalão, state of Goiás, Brazil, including aspects of morphology, floral biology, energy availability from nectar, and reproductive system. Geissomeria pubescens has pendulous red flowers, tubular corolla, diurnal anthesis, and no odor. These floral traits characterize G. pubescens as an ornithophilous species. The total amount of energy available from nectar was 8.60 ± 2.87 cal·flower–1, and each individual produced up to 22.53 cal·day–1. Based on the resources offered by G. pubescens, the fragment studied may support up to 94.6 hummingbirds during the peak of nectar availability. Hummingbirds were the only flower visitors, and Thalurania furcata (Gmelin, 1788) was the main pollinator. Flowers from manual cross- and self-pollination treatments produced fruits, but fruit set was low compared with open pollination. These results, along with the lack of fruit set from agamospermy and spontaneous selfing, demonstrate the importance of hummingbirds for pollen flow and, consequently, for fruit formation in G. pubescens.

Floral, reproductive and pollinators biology of <i>Myrcianthes pungens</i> (Berg) Legrand, neglected species

“…(2) beginning of the anthesis; (3) total anthesis; (4) early senescence), were kept in a phenolic sponge in a natural environment, throughout the evaluation period. For the observation, 3% hydrogen peroxide were use, which through the peroxidase activity promoted the bubbling on the stigma, thus confirming the receptivity of the same (Kiill, Martins, & Silva, 2014;Versieux et al, 2014;Matias & Consolaro, 2014).…”

“…Few bees were observed, however, being the first visitors in the morning, which showed preference for flowers at the beginning of the anthesis, remaining on the reproductive structures for approximately 5 seconds. Although they are legitimate visitors, the bees observed were characterize in this case as occasional pollinators due to less frequent visits (Matias & Consolaro, 2014). The main resource sought in this case are the pollen grains.…”

“…The moths identified in the nocturnal period (Ettiela sp., Elasmupalpus sp. (Pyralidae)) were observed moving between the flowers, always touching both reproductive structures, remaining in the flower for approximately 5 seconds, being characterized as effective pollinators of guabiju tree, also due to frequent visits in the observed period (Matias & Consolaro, 2014).…”

“…The identified flies and wasps were observed moving between the flowers of the same plant, sometimes touching both reproductive structures, thus being able to be characterized as occasional guabiju pollinators (Matias & Consolaro, 2014). According to Faegri and Van der Pijl (1979) flies are not stimulated to visit special parts of the flowers such as anthers or stigma but rather due to the foul odor that becomes attractive for oviposition, ensuring food for the larvae.…”

“…Pollinators were those who made frequent and legitimate visits (contact in all reproductive structures), occasional pollinators those who presented less frequent visits, even being a legitimate visitor and plunderers those who do not make contact with the reproductive structures (Matias & Consolaro, 2014).…”