Cow-tongue fern is a plant species that belongs to the Polypodiaceae family, and it can also be known by other names. Its scientific name is Phlebodium aureum, and it can be referred to as golden polypody or river fern. Some people may recognize it as blue star fern, due to its unique blue-green color appearance. Others may use the term blue rabbit's foot fern, due to the furry rhizomes that grow out of the soil. The leaves of this unique fern can vary in shape, from long and narrow to broad and lobed. It can also be referred to as holly fern, due to the resemblance of the leaves to holly bushes. Whatever the name, cow-tongue fern is a fascinating plant to observe and has its unique qualities that make it stand out.