Athyrium Thelypteroides is a type of fern that is commonly known as silvery spleenwort. Unfortunately, there are very few synonyms for this plant name as it is a specific species, and synonyms are usually reserved for broader plant classifications. However, there are many different varieties of spleenwort, some of which are closely related to Athyrium Thelypteroides, and may share similar features. Some of these varieties include black spleenwort, mountain spleenwort, and American spleenwort. While these varieties are not synonyms for Athyrium Thelypteroides, they may be helpful to know or research if you are interested in plants in the spleenwort family.