Erva-do-ferro!

Prunella vulgaris

A erva-do-ferro tem nas falas galegas estes nomes:
brunela
consolda-menor
erva-das-feridas
erva-de-são-joão
erva-do-ferrol
erva-do-forrol
erva-ferrona
junta-carne
planta-do-forrol
prunela.

A planta tem um uso conhecido vulnerário, isto é para feridas.

Enigmático o nome de ferro.
Então buscando acho que:
The organic fraction (OF; 25.7% w/w of rosmarinic acid) of Prunella vulgaris (total extract) was found to exhibit the following: scavenging activity on diphenylpicrylhydrazyl radical (DPPH), inhibition of in vitro human LDL Cu(II)-mediated oxidation, protection of rat mitochondria and rat hepatocytes exposed to either tert-butyl hydroperoxide, or to Cu(II) and Fe(III) ions. OF also showed a potential to inhibit rat erythrocyte haemolysis and it reduced the production of LTB(4) in bovine PMNL generated by the 5-lipoxygenase pathway. Other observations included antiproliferative effects against HaCaT cells and mouse epidermal fibroblasts and a moderate OF antimicrobial activity on gram-positive bacteria. Rosmarinic, caffeic and 3-(3,4-dihydroxyphenyl)lactic acids exhibited less potent activity than the plant extract in all bioassays. The antioxidative, antimicrobial, together with antiviral effects offer good prospects for the medicinal applications of P. vulgaris. (http://www.ncbi.nlm.nih.gov/pubmed/14595592)

Então, com relativa probabilidade a sua atividade detoxicante do ferro, já for em minérios ou noutras atividades, era conhecida!