Blepharidium guatemalense, an obligate nickel hyperaccumulator plant from non-ultramafic soils in Mexico

Nickel hyperaccumulation in Blepharidium guatemalense Standl. (Rubiaceae) was found the tropical forests of south-eastern Mexico. This study aimed to document geographic extent nickel this species, understand its process and explore distribution within tissues plant. To accomplish these objectives, a complete non-destructive elemental screening herbarium specimens performed with hand-held X-ray fluorescence spectrometer. Besides, rhizosphere soils plant were collected Mexico analyzed for physical–chemical parameters. Finally, maps other elements obtained by spectroscopy microscopy. revealed that is distributed throughout Chiapas, Tabasco Campeche, reaching maximum concentration leaves (4.3 wt%) followed roots seeds (2.0 bark (1.8 wt%). Simultaneous cobalt 15% specimens. has uncommon re-distribution mechanisms via phloem since tissue highest nickel-enriched from all parts (from leaves). A high total (mean 610 µg g−1) even though no evidence ophiolite emplacement area been reported. represents first hypernickelophore (> 1 wt% Ni) be reported as growing are neither ultramafic nor enriched anthropogenic pollutants.