A strong correlation has been found between the levels of nickel and citric acid in the leaves
of 17 New Caledonian plant species which show a range of nickel-accumulating ability:
Sebertia acuminata, Psychotria douarrei, Geissois pruinosa, Hybanthus austrocaledonicus,
Hybanthus caledonicus, and 12 species of Homalium. Purified extracts of these plants
contain nickel as a citrate complex. Three nickel-accumulating plants from beyond New
Caledonia (Alyssum bertolonii, Alyssum serpyllifolium s. sp. lusitanicum and Pearsonia …