I've been looking at WP:NC (flora), which seems to be quite definite about this situation.  It says that the product should have an article under that name, the species under its scientific name, and of course the genus gets its own article.  I have therefore divided the information as follows:
Humulus (formerly Hop (plant)).  Information covering all species.  Cultivation, history etc information (all relevant only to one species) moved to Hops.
Humulus lupus.  Botanical information.
Hops.  History, uses, cultivation etc.  Incorporate information from Hop (plant).  Now some duplication.

I hope this all looks OK...