Good call Rumacara, I use that kind of stuff for my jungle terrain too, and it's usually pretty cheap to boot
For the ruin bases I used a combo of Woodland scenic scatter, scatter flowers, Noch static grass types, Hornby bush branches for the saplings and Army Painter flowers and grass tufts.
I find that just looking at pictures of nature on-line, or even just out the window(!) gives me heaps of inspiration for this stuff, mixing up multiple lengths and colours of flock in a natural looking way seems to work OK for the stuff I do
Cheers