Hollyfern

Hollyferns are species of mountain ferns that are assigned to the taxonomic genus Polystichum. It is also one of ten largest genera of ferns with over 260 species worldwide! The genus finds most of its diversity in Eastern Asia, with about 120 species in China alone. the region from Brazil to Mexico has nearly 100 species, Africa is home to 17 species, North America with 15 species, and Europe around 5 species.

Body Design
One distinguishable characteristic of hollyferns is rhizomes. Ferns have a bundle of stems called a rhizome, which not only anchors the fern to substrates, but absorbs water and minerals through the means of thin, hairlike fibrous roots. The rhizome of the Western sword fern is covered by small reddish-brown scales, and thin vestigial leaves that serve as protection for the rhizome.

The leaves of the fern, called fronds, begin as small coils called fiddleheads. The fiddleheads then grow and unravel, becoming the leaves of the fern. the fronds have a stalk that connects them to the rest of the plant, and runs the entire length of the frond. The stalk can be divided in two parts: the stipe, the section before any leafy tissue, and the rachis, the section with leafy tissue. The small leaflets on the frond are called pinnae (singular: pinna). On the underside of the pinnae are small spore casings, or sporangia. The sporangia may clump together to form sori (singular: sorus).

Life Cycle
The Fern life cycle revolves around the alternation of generations, as the case with many plants, and begins within the sporangia when a haploid spore is produced through a type of cell division called meiosis.

When the spores are released from the sporangia, that then grow to form a small heart shaped, haploid gametophyte called a prothallus. The prothallus has both male and female sex organs. The sperm will then travel over a thin film of water to the egg, and create a zygote. The zygote remains attached to the prothallus as it grows into an embryo. As the embryo grows into a mature sporophyte, the prothallus dies.

Ecology
Many believe that the ecology of Hollyferns is dependent upon the amount of liquid water in the region, because their reproduction requires water for fertilization. To some extent this is true, but ferns are very hardy plants that can adapt to many conditions. They are also great at indicating their needs, as some will only grow near running water or only where there is deep soil.

The greatest area of diversity for hollyferns is in Eastern Asia, where there are over 100 species in the landscapes from japan to the himalayas. Polystichum are ferns of the mountains. Near the equator they are never found below an elevation of 1000m. Members of the genus polystichum live on or among rocks, and grow particularly well in talus. Disturbed wetlands are also favorites of hollyferns, some of the most polystichum-rich places in the world being in Japanese forest plantations.

Medicinal and Culinary Uses
Ferns are very commonly used house and garden plants. Ferns add moisture and stability to soil. Beyond that they have health and culinary uses as well.

The oil from the roots of some male ferns plants can be used to expel some parasitic worms from humans. The Christmas fern (Polystichum acrostichoides) has even been known to treat rheumatism. Ferns can also be prepared in to dishes as they are a good source of carbohydrates. the fiddleheads can be boiled with salt to remove the small hairs and scales, some are even considered a delicacy.

Video
Polystichum munitum, Western Sword fern ro5fP93UMqk