yea, it is a shortened form of the spanish word "potiguaya", which means marijuana leaves.

And, according to legend, the term "marijuana" ... spelled "mariHuana" in mexico, is a term that originated between 1890-1895, when marijuana cultivation first began to be cultivated on a large scale in Mexico (and while it was still legal). It refers to a famous couple that was well-known for marijuana cultivation ... Mary Juan (not sure what the guys name was).

Any other questions?