US Fissiden (Fissidens fontanus), is a North American aquatic moss that has recently been gaining popularity in the freshwater aquarium hobby. This plant is a very fluffy, lush green plant that will attach to most surfaces and can eventually grow into a large mat of impressive size. Like many similar plants, it provides refuge for shrimp and fish fry and makes for an attractive and useful grazing area for shrimp. It can be easily attached to driftwood and rockwork. It is slow-growing and requires low to moderate light.

US Fissiden is a very easy plant to keep without much extra care, but like all plants, it can benefit from CO₂ supplementation, although this is not required. Like many mosses, it does not typically respond positively to most chemical plant supplements. Many aquarists report success with this moss purely through keeping a well-maintained aquarium with no supplementation.