User blog comment:Kogath/Monster Hunter Frontier G6 Discussion/@comment-7784930-20150213054535/@comment-17735225-20150216025140

I'll take a wild guess and say that the cactus will boost Varusa's power dramatically if eaten. Might probably change the colour of its horn tips and wing membranes. So it's the best not to let it take that nasty snack.

Or protect the cactus for research thing, which seems to be so from early previews.