The term hyperaccumulator, referring to a plant with a highly abnormal level of metal accumulation, was originally coined to describe a plant with a concentration exceeding 0.1% Ni (dry mass) and then extended to other metals such as Co and Pb (0.1% threshold value) and Zn and Mn (1% threshold value). To date ~400 known metal hyperaccumulators have been reported worldwide. The most widely referred to have been the mustard (Thlaspi caerulescens) containing 1-2% Zn, Alyssum lesbiacum (>1% of Ni), and the New Caledonian tree Sebertia acuminata whose latex was reported to contain above 20% Ni (dry mass).

The discovery of such metal-hyperaccumulating properties in certain plants spurred research towards using them for cleanup of heavy-metal-contaminated soils.