Contrasting nickel and manganese accumulation and localization in New Caledonian Cunoniaceae

Abstract Purpose The Cunoniaceae are a major component of the New Caledonian flora with 91 endemic species that highly unusual in multiple metals hyperaccumulated different species. This makes it an ideal model system for studying nature hyperaccumulation phenomenon. Methods X-ray fluorescence spectroscopy (XRF) scanning all herbarium collections was undertaken at Herbarium Caledonia to reveal incidences nickel (Ni) and manganese (Mn) accumulation. Following on, Mn hyperaccumulating P. reticulata Ni xaragurensis were selected detailed follow-up investigations using synchrotron-based microscopy (XFM). Results systematic XRF screening specimens showed numerous have high foliar either accumulating or Mn, but not both elements simultaneously. Soil ‘extractable’ concentrations associated Pancheria greatly varies between XFM data shows has distinctive distribution pattern concentrated large hypodermal cells. contrasts where mainly localized around epidermis, cells observed. Conclusions Manganese accumulation differently growing on ultramafic soils, which is explained by contrasting soils conditions, represents ecophysiological adaptations.