Polystichum acrostichoides, commonly known as Christmas fern, is a species of fern native to the eastern United States. It is a popular ornamental plant, valued for its evergreen fronds that remain green throughout the winter season. Despite its common name, there are several synonyms for P. acrostichoides, including Dryopteris acrostichoides and Cyrtomium acrostichoides. The use of synonyms is common in the scientific naming of plants, as different taxonomists may classify the same organism under different names. However, regardless of the name used, the beauty and hardiness of the Christmas fern remains unchanged.