In one box of stuff in the Loft Full Of Lead, I found these Armorcast alien plants from many years ago. They won’t take much to get painted using a few colours and a wash.
I have two more, some giant man eating plants.
Some time ago on the No Limits forum there was a discussion about some terrain rules. Plants like those above were something that were to be included. How that I have some time on my hands, I will write up some draft rules.