I bought these plastic aquarium plants a while back. Mine came attached to a circular frame, but other people have seen them on flat mats. At the time I thought they could be useful for my toy soldier terrain.
The problem, as I saw it, was the large disc at the base of the tufts which was used to affix them to their frame. I could not figure out how to disguise it.
Then at Adelaide I spoke to a tremendously friendly chap who had a scintillating Aztec game set up. He had the exact same plastic foliage stuck to simple bases. They looked grand.
“What’s your secret?” I asked.
“Go hard with the flock,” he advised.
And his work looked great. The intrusive disc/cup looked just like a bulging part of the plant base.
Here is the start of my attempt to recreate this great application. I have glued two tufts to thin card about 5.5cm in diameter. I have textured the base a little with some polyfiller, and have given the a coat of Raw Umber.
The next step is to highlight with a dusty tan, and then go heavy with that flock. Finished photos to come when I get the chance to do some real work (other than having to go to work).
BEUZEVILLE 
Looking good Andrew.
What did you attach the tufts to the card with? That waxy plastic can be hard to glue. I have heard that hot glue works well, but I havent put that to the test personally yet.
Araldite, a two part epoxy glue. Like you, I figured anything else would be a failure. Wait for the final product before dishing out the praise. They could still turn out pants.