Alyssum murale

However, some plants can accumulate more than 0.1% of Pb, Co, Cr, and more than 1% of Mn, Ni and Zn in the shoots. These accumulator plants are called hyperaccumulators. To date, there are approximately 400 known metal hyperaccumulator plants in the world (Baker and Walker, 1989). Thlaspi caerulescens, Alyssum murale, A. lesbiacum, A. tenium are Zn and Cd hyperaccumulators. Brassica juncea, a high-biomass plant, can accumulate Pb, Cr(III), Cd, Cu, Ni, Zn, Sr, B and Se. Thlaspi caerulescens accumulates Ni. Hybrid poplar trees are reported to phytoremediate Cd and As contaminated soils. A Chinese brake fem, Pteris vittata, is an As hyperaccumulator (Ma et al., 2001). 

Another alternative hypothesis about the biological role of hyperaccumulation was the increase of osmotic pressure for increased tolerance to the drought stress that often characterizes the natural habitats of hyper accumulators. This hypothesis, however, was falsified by a study with the Ni hyperaccumulator Alyssum murale and the Cd/Zn hyperaccumulator T. caerulescens [53]. 

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