Plant Systematics and Evolution

, Volume 254, Issue 3–4, pp 185–197

Pollination success in monochromic yellow populations of the rewardless orchid Dactylorhiza sambucina

Article

DOI: 10.1007/s00606-005-0338-0

Cite this article as:
Kropf, M. & Renner, S.S. Plant Syst. Evol. (2005) 254: 185. doi:10.1007/s00606-005-0338-0
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Abstract

Dactylorhiza sambucina is a European terrestrial orchid that lacks a pollinator reward. Throughout most of its range, populations contain yellow- and purple-flowering individuals, but in western Germany, monomorphic yellow populations predominate. As elsewhere, bumblebee queens are the most important pollinators in these populations, and mean fruit set over two years was 19%, well within the range reported from dimorphic populations. Multivariate analyses of plant and population traits, including plant height, leaf number, flower number and density on the spikes, flowering population density, and nearest neighbor distance, showed that only individual plant height and population density had a unique positive effect on pollen export; female function was unrelated to height or population density. The positive effects of dense spacing of flowering conspecifics and tall size appear due to greater visual attractiveness. Good visual exposure may also explain that flowers higher up on the spikes, in spite of opening late in the season, had higher male reproductive success than early flowers.

Keywords

Bumblebees Dactylorhiza sambucina flower color dimorphism monochromic populations pollination success rewardless flowers 

Copyright information

© Springer-Verlag Wien 2005

Authors and Affiliations

  1. 1.Institut für BotanikBOKU - University of Natural Resources and Applied Life SciencesViennaAustria
  2. 2.Systematische BotanikLudwig-Maximilians UniversityMunichGermany

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