Figure 2.

Psychotria gabriellae and Psychotria semperflorens as a model system to study nickel hyperaccumulation. The Ni hyperaccumulator P. gabriellae (red tag) and the closely related non-accumulator P. semperflorens (yellow tag) are living in sympatry in rain forest on ultramafic soil in New Caledonia (A). Both species are 1–3 meters shrub with very similar pink flowers (top right insert: P. semperflorens inflorescence). In natural growth condition, P. gabriellae accumulates up to 4% Ni in leaves while P. semperflorens accumulates approximately 100 times less Ni. These differences can be semi-quantitatively visualized on XRF spectra (B).