In article , Salty Thumb of
Death writes

Does anyone one know why it's called dead nettle? Something to do with
death or is it a corruption of some other language? Is it true that it's
presence indicates heavy metals (particularly lead) in the soil? From
hearsay, I've gathered that it tends to grow in 'wasteland' which makes
sense if the part about heavy metals is true.

White dead nettle, _Lamium album_, when not in flower, looks very like a
true nettle, _Urtica dioica_. I conjecture that the name dead (meaning
non-stinging) nettle was originally applied to this species, and
subsequently extended to other species of _Lamium_.

In my younger days I was led to believe that the resemblance of _Lamium
album_ to _Urtica dioica_ was a case of mimicry - for purposes of
herbivore deterrence. Now I'm not sure whether that is true, or an urban
legend - as herbivores do consume nettles, and as herbivores may well
recognise plants by smell, rather than sight.

_Lamium album_ is not the only plant that can be mistaken for a nettle;
one of the British species of _Stachys_ can fool me (again when out of
flower). The hemp-nettles are quite so similar.
--
Stewart Robert Hinsley