Pakpak-lawin is a large xerophyte, belonging to the fern family Polypodiaceae. Rhizome is creeping, stout and fleshy, with narrow, brown to blackish short-ciliate scales about 1 centimeter long. Leaves are of two kinds: cup-leaves and the fertile fronds. Cup-leaves are humus gathering fronds, brown and shiny when mature, ovate, coriaceous, somewhat imbricate, 15 to 30 centimeters long, 5 to 20 centimeters wide, concave, shallowly lobed below and deeply so above. Fertile fronds are long, pinnately lobed, on stipes 20 to 30 centimeters long. Sori are 40 to 120 centimeters in length; lobes are rather large and arranged in tow rows between the main veins.
Fern is a vascular, seedless plant that belongs to the group Pteridophyta. There are around 12 000 types of ferns that differ in size, morphology and type of habitat. Ferns can be found throughout the world. They live in shady places that provide enough moisture, such as forests, fields, swamps and areas near the streams. Fern can survive in various climates and on different altitudes. These plants are among the oldest living organisms on the planet. People use ferns mostly in decorative purposes. Several types of ferns are known as invasive species due to increased reproduction rate and ability to occupy new habitats quickly. Some species of ferns are listed as endangered because of the habitat loss (as a result of increased human activity).
