I think I can safely assert the people of the US don't even have a pronunciation for St John's wort, because until recently nobody had ever even heard of it.

So when it began to appear in the news, we simply sounded it out and made it rhyme with 'sort,' 'Mort' and 'short'.

I agree with you about 'gifted.' I believe that the form 'He gifted it to the school...' originated with lawyers. In the US, there is a combined estate and gift tax. It's a package deal which prevents the wealthy from avoiding estate taxes by giving away assets right and left when death seems imminent. There are limits on how much one can give away, and how soon before death they can be given.

Lawyers have become so focused on the word gift from 'estate and gift tax' that they started using the form 'gifted' instead of 'gave.'   

If I presented you with a necklace of Czech glass beads, a lawyer would say I gave it to you. But if I gave you $30,000, kept a record and paid tax on it, the lawyer would say I gifted it.

I believe that people sensed that 'gifted' was associated with wealth and prestige, and they copied.