• Marattiales
• Christenseniales

The Marattiopsida are primitive ferns that are quite different from many plants familiar to people in temperate zones. Many of them have massive, fleshy rootstocks and the largest known fronds of any fern. In this group, such fronds are found in the genus Angiopteris , native to Australasia and Oceania. These fronds may be up to 7.5 meters (25 feet) long.

This group also contains the King Fern , Marattia salicina, known in Maori as Para. Sometimes called the Potatoe Fern, this is a large Australasian fern with an edible fleshy rhizome that is used as a food source by some indigenous peoples. The smaller plants of genus Danaea are native to the Neotropic.