Thelypteris phegopteris is commonly known as beech fern, mountain fern, and narrow beech fern. Other synonyms for this plant include Dryopteris phegopteris, Polypodium phegopteris, and Nephrodium phegopteris. This plant is a deciduous, shade-loving fern indigenous to the temperate regions of Europe and North America. The delicate fronds of the fern have triangular-shaped leaflets and stand upright from a central crown. The beech fern prefers damp, acidic soil and can be found growing on rocky slopes, stream banks, and in shaded forests. The fern's unique leaf structure and elegant shape make it a popular choice for woodland gardens and shady borders.