Cnidusa

The cnidusa is a hybrid of swamp beans and ferrumtine. It replaced swamp beans but not ferrumtine. When both species absorbed organic particles some got stuck eating each other and fused into one species. Cnidusa resemble the shape of swamp beans but are twice their size. They are also hollow now and bring in water via the flagellum of the ferrumtine which is in the opening and insides. This brings in organic particles as well as iron from the rusty soil. It can absorb both.This helps it build a stronger structure. Once taken in the water is expelled out of holes along the lower sides.

Due to their large concentration of iron in them they are a prime target for "iron eaters".They also sink to the bottom of the river because of the irons weight.