Make one post-type the taxonomy of another post-type

Howdy! :sunglasses:

I’m trying to set-up a plant database with custompress – pretty similar to the one you describe on the usage-tab of the plugin-page – but with two instances. So instead of just one post-type (“plants”:wink:, I want it to also have a second post-type for the different “varieties”. Also “plants” should be the taxonomy for “varieties” or the parent element.

Any ideas? Is it even possible?

Thank’s for the help!