King fern

The King fern (Ptisana salicina, formerly Marattia salicina) is a large, coarse fern native to Australia, New Zealand, and other parts of Oceania and Southeast Asia. It is characterized by its massive, erect fronds which can grow up to 5 meters (16 feet) long and 1 meter (3.3 feet) wide. These fronds are bipinnate to tripinnate, meaning they are divided into leaflets that are themselves divided.

The King fern is typically found in damp, sheltered habitats such as rainforests, gullies, and near streams. It prefers well-drained, humus-rich soil.

The sori (spore-bearing structures) are located along the margins of the pinnules, appearing as narrow, elongated lines. Unlike many ferns, King ferns have fleshy, tuber-like rhizomes that can store water and nutrients, aiding in their survival during periods of drought. These rhizomes were historically used as a food source by indigenous populations in some regions.

The plant can be propagated by spores or by division of the rhizomes. Due to its large size, it is primarily grown in botanical gardens or large private gardens with suitable conditions. The King fern is considered an ancient species, with fossil records indicating its presence millions of years ago.

It is sometimes referred to as the Para fern or Potato fern, the latter referencing the starchy rhizomes.