Pollination biology of four sympatric species of Habenaria (Orchidaceae: Orchidinae) from southern Brazil

Authors

  • Marcelo Pedron,

    1. Departamento de Botânica, Programa de Pós-graduação em Botânica, Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Porto Alegre, Rio Grande do Sul, Brazil
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  • Cristiano Roberto Buzatto,

    1. Departamento de Botânica, Programa de Pós-graduação em Botânica, Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Porto Alegre, Rio Grande do Sul, Brazil
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  • Rodrigo B. Singer,

    Corresponding author
    • Departamento de Botânica, Programa de Pós-graduação em Botânica, Universidade Federal do Rio Grande do Sul, Instituto de Biociências, Porto Alegre, Rio Grande do Sul, Brazil
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  • João A. N. Batista,

    1. Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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  • Alfred Moser

    1. Av. W. Rotermund 1045. Morro do Espelho, São Leopoldo, Rio Grande do Sul, Brazil
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Corresponding author. E-mail: rbsinger1@yahoo.com

Abstract

The pollination process and breeding system of the sympatric Habenaria johannensis, H. macronectar, H. megapotamensis and H. montevidensis was documented for native populations from Rio Grande do Sul, Brazil. All species investigated offer a nectar reward (mean values of total sugars ranging from 18 to 26%) concealed in a spur. Habenaria montevidensis is pollinated by butterflies (Hesperiidae, especially of the genus Urbanus) that carry pollinaria on their eyes; the other three species are pollinated by Sphingidae. Habenaria johannensis is pollinated by the moths Manduca rustica and M. sexta that carry the pollinaria at the base of the proboscis. Habenaria macronectar is pollinated by the moths Eumorpha labrusca and M. cf. lucetius, and these bear pollinaria between the palpi. Habenaria megapotamensis is pollinated by moths of M. cf. lucetius that bear the pollinaria on the proboscis. All species studied are self-compatible, but pollinator dependent. They also displayed high reproductive success (ranging from 69.48 to 97.40%) and male efficiency factors slightly higher than 1, suggesting that at least one flower was pollinated for each flower acting as pollen donor. At the study sites, the investigated Habenaria spp. are isolated (in terms of pollination) by a set of factors that includes differing floral morphologies, different pollinators and/or different pollinarium placement on the pollinator. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ••, ••–••.

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