Heavy Metal Plant LIVES ON ROCK

Bornmuellera baldaccii  on metal-rich soil

Photo: Bornmuellera bal­dac­cii on the upper slopes of Mt Smolikas by Cecchi et al.

If plants did rock out at con­certs then the one above would def­in­itely be Bornmuellera to be wild. Some plants like to be in sun­light in well-drained soils. Others need moist pot­ting and the shade. Bornmuellera bal­dac­cii in con­trast likes ultramafic soil. This is soil made from the kind of igneous rocks, sim­ilar to the rock you’d find in the mantle. When it breaks down into soil, it’s low in silica but high in heavy metals like chro­mium and nickel. It’s the kind of soil that would nor­mally be toxic to plants.

As Cecchi et al. explain, Bornmuellera bal­dac­cii can live in these con­di­tions because it is no ordin­ary plant, it’s a Nickel hyper­ac­cu­mu­lator. Its abil­ity to sur­vive in toxic envir­on­ments could make it use­ful to help clean up pol­luted sites. Cecchi’s paper also intro­duced me to the concept of phytomin­ing. If a plant can hyper­ac­cu­mu­late nickel then it’s hold­ing on to a valu­able asset. Harvesting it and burn­ing it would yield nickel-rich ash — which you can pro­cess for nickel.

It’s not a trait that every plant has, but some oth­ers do. One is Leptoplax (Peltaria) emarginata. Until now people thought it was related to a non-hyperaccumulator plant in the tribe Thlaspideae. The hyper­ac­cu­mu­lator abil­it­ies in L. emarginata led to a molecu­lar study that showed it was rel­at­ive to Bornmuellera bal­dac­cii. It means it’s in a dif­fer­ent tribe, the Alysseae.

Getting the fam­ily tree right means that we can have a bet­ter idea of what happened when. Cecchi et al’s study also shows that hyper­ac­cu­mu­la­tion wasn’t a one-off event. It seems that hyper­ac­cu­mu­la­tion is a skill that can be evolved or lost by plants in the Alysseae tribe to take advant­age of eco­lo­gical niches when they happen.

It seems that Bornmuellera bal­dac­cii’s ancest­ors chose to take the hard way to suc­cess so they could live among hard rock. If hyper­ac­cu­mu­lat­ors can be used to clean up messes, then they could have a long and prof­it­able rela­tion­ship with heavy metal.

You can read the full art­icle for free at Annals of Botany.

Cecchi L., Gabbrielli R., Arnetoli M., Gonnelli C., Hasko A. & Selvi F. (2010). Evolutionary lin­eages of nickel hyper­ac­cu­mu­la­tion and sys­tem­at­ics in European Alysseae (Brassicaceae): evid­ence from nrDNA sequence data, Annals of Botany, 106 (5) 751–767. DOI:

Alun Salt. ORCID 0000-0002-1261-4283

When he's not the web developer for AoB Blog, Alun Salt researches something that could be mistaken for the archaeology of science. His current research is about whether there's such a thing as scientific heritage and if there is how would you recognise it?

Pin It on Pinterest

Liked this?

Be the first to share this post with your friends!