In article ,
Brian wrote:

Can we just pretend we meant Horsetail all the time?

We don't need to pretend! The term Mare's Tail refers to two plants,
and it is the Equisetum that is meant here. Just as Bluebell refers
to two plants, depending on where you are in the UK. If you want to
be botanically precise, use botanical Latin.

Horsetail is nowhere mentioned as a local name for Mare's-tail. It does
feature, however, as a 'frequently mis-identified'!

That would mean that Horsetail was the name for two plants! The
situation is the other way round, and the use of Mare's Tail for
Equisetum is widespread and patchy rather than local.

Your supposition would beg the question: "If Horsetail is known locally as
Mare's-tail then what is the local name for Mare's-tail?"

Why should it have one? There aren't common names for every plant,
and it isn't rare for one common name to relate to two unrelated
plants. Samphire is another example.

Your analogy with bluebells is widely known; so much so that it is
customary to give a national prefix~English, Spanish and Scottish etc. They
are all flowering plants unlike the 'tails.

The normal use is just "bluebell". People will qualify as and when
they feel it necessary. Learn to live with the chaos that is normal
English usage :-)


Regards,
Nick Maclaren.