from the above readings, it looks like carp will eat it.
You can give them a try - and please do; but I know of several instances where GC were ineffective on this plant species.
I can't imagine slender spikerush ranking very high on their food-preference list - especially due to its physiology and growth-habits - and the GC's feeding-mechanics, but I suppose they'd try to eat it if nothing else (more desirable) is available.
