The occurrence of crassulacean acid metabolism in epiphytic ferns, with an emphasis on the vittariaceae

Shannon L. Martin, Ryan Davis, Piero Protti, Teng Chiu Lin, Shin Hwei Lin, Craig E. Martin

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16 Citations (Scopus)


The potential for nighttime CO2 uptake and/or increases in tissue acidity characteristic of crassulacean acid metabolism (CAM) was investigated, to varying degrees, in 12 species of Vittariaceae as well as in seven species in four other families of tropical epiphytic ferns. Evidence of CAM (actually CAM cycling, i.e., diel changes in tissue acidity without nighttime atmospheric CO2 uptake), though highly variable, was found in two species of Vittariaceae. The ecophysiological significance of this finding is puzzling, because the occurrence of these plants in deeply shaded, extremely moist habitats is rare, if not unique, among plants expressing any degree of CAM. The results of this study confirm that CAM among the ferns is not limited to the Polypodiaceae, and they emphasize the polyphyletic nature of the evolution of CAM among higher plants.

Original languageEnglish
Pages (from-to)623-630
Number of pages8
JournalInternational Journal of Plant Sciences
Issue number4
Publication statusPublished - 2005 Jul



  • CAM cycling
  • Crassulacean acid metabolism (CAM)
  • Epiphytes
  • Evolution
  • Ferns
  • Photosynthesis
  • Vittariaceae

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Plant Science

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