Peppermint

Peppermint

Mentha x piperita

So, what is the difference between Spearmint, Peppermint and Water Mint?  Apparently it's not a simple matter.  You think it would be, given the popularity of chewing gum, but the plant taxonomists like to put a wrinkle in everything.

Spearmint (Mentha spicata) is an introduced species in Indiana.  Water Mint (Mentha aquatica) is also an introduced species.  Try to find Peppermint in a field guide and it will be missing, because it is now considered to be a cross between Spearmint and Water Mint.

Apparently, Peppermint has confused everyone since the beginning.  Linnaeus treated it as a species - Mentha piperita.  Somebody somewhere along the line decided that it was a cross between Spearmint and Water Mint and so put the 'x' in the scientific name.

The problem now is what to call it.  Since it's not a species, the field guide people don't want to put it in their books, but it's out there anyway, so what to do?  Answer ... call it Water Mint!  Or, call it Peppermint!  Or, don't put it in there since it's not a species!  Sheesh, poor Peppermint, it gets no respect.

Peppermint is generally found near water

Peppermint flowerheads are thicker and more compact than Spearmint.

Peppermint leaves have stems, whereas Spearmint leaves do not