In article ,
Kay wrote:

You have forgotten Urtica pilulifera, the Roman or small nettle,
I think.

It's not in Stace and therefore I presume not UK. I've certainly never
seen it here.

Upon checking with CTW (of 30 years back), it was classed as a
formerly rare alien, possible extinct. Either it is definitely
extinct or has been Expelled From The British Flora As Not A
Native Plant. Botany has its Howards, Blunketts and Clarkes, too.

Exactly how you determine whether a plant like that (i.e. rare,
hence absence of pollen is no evidence of absence, and been known
since time immemorial) was introduced by the Romans or by passing
birds, don't ask me. One would make it an alien and the other a
native. But there's no arguing with dogma.



Regards,
Nick Maclaren.