Depending on how dense the grass/bamboo is you could do something like this. It is, at least in every way I can think of, easier to map with deciduous trees like in that than bamboo but something more spiky might look like bamboo from above. Here is a map with junglely forests that perhaps could inspire a pattern in the same design as Lerbwic. This is much more zoomed in than that but with shadows and enough spikeyness it might work out.
This is, of course, just an idea though. Others here - yourself included - can easily come up with something else (and I am unsure of how effective this idea might be). I am merely meaning this to be a possible inspiration/example.