The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Most tree ferns are members of the "core tree ferns", belonging to the families Cyatheaceae, Dicksoniaceae, Metaxyaceae, and Cibotiaceae in the order Cyatheales. It is estimated that Cyatheales originated in the early Jurassic, and is the third group of ferns known to have given rise to tree-like forms. The others are the extinct Tempskya of uncertain position, and Osmundales where the extinct Guaireaceae and some members of Osmundaceae also grew into trees. In addition there was the Psaroniaceae and Tietea in the Marattiales, which is the sister group to true ferns.
A fern is a member of a group of vascular plants that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except the lycopods, and differ from mosses and other bryophytes by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae) and eusporangiate ferns, the latter group including horsetails, whisk ferns, marattioid ferns, and ophioglossoid ferns.
Lygodium is a genus of about 40 species of ferns, native to tropical regions across the world, with a few temperate species in eastern Asia and eastern North America. It is the sole genus in the family Lygodiaceae in the Pteridophyte Phylogeny Group classification of 2016. Alternatively, the genus may be placed as the only genus in the subfamily Lygodioideae of a more broadly defined family Schizaeaceae, the family placement used in Plants of the World Online as of November 2019.
The Dryopteridaceae are a family of leptosporangiate ferns in the order Polypodiales. They are known colloquially as the wood ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family is placed in the suborder Polypodiineae. Alternatively, it may be treated as the subfamily Dryopteridoideae of a very broadly defined family Polypodiaceae sensu lato.
Platycerium is a genus of about 18 fern species in the polypod family, Polypodiaceae. Ferns in this genus are widely known as staghorn or elkhorn ferns due to their uniquely shaped fronds. This genus is epiphytic and is native to tropical and temperate areas of South America, Africa, Southeast Asia, Australia, and New Guinea.
Gymnocarpium dryopteris, the western oakfern, common oak fern, oak fern, or northern oak fern, is a deciduous fern of the family Cystopteridaceae. It is widespread across much of North America and Eurasia. It has been found in Canada, the United States, Greenland, China, Japan, Korea, Russia, and most of Europe.
Polystichum acrostichoides, commonly denominated Christmas fern, is a perennial, evergreen fern native to eastern North America, from Nova Scotia west to Minnesota and south to Florida and eastern Texas. It is one of the most common ferns in eastern North America, being found in moist and shady habitats in woodlands, stream banks and rocky slopes. The common name derives from the evergreen fronds, which are often still green at Christmas.
Onocleaceae is a small family of terrestrial ferns in the order Polypodiales. It is placed in the suborder Aspleniineae in the Pteridophyte Phylogeny Group classification of 2016. Alternatively, the family, along with Blechnaceae, may be placed in a very broadly defined family Aspleniaceae as the subfamily Blechnoideae. The family may contain from one to four genera, consisting of five species largely in north temperate climes. The four genera, Matteuccia, Onoclea, Onocleopsis and Pentarhizidium, may be included under the single genus Onoclea.
Tectaria is a genus of fern in the family Tectariaceae, according to the Pteridophyte Phylogeny Group classification of 2016. Halberd fern is a common name for species in this genus.
Gymnocarpium is a small genus of ferns, called oak ferns. It was once placed with various other groups, including the dryopteroid ferns and the athyrioid ferns. Cladistic analysis has demonstrated that Gymnocarpium and Cystopteris form a natural but relatively primitive clade that is basal to the asplenioid, thelypterioid, and athyrioid ferns comprehensively.
Tectariaceae is a family of leptosporangiate ferns in the order Polypodiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family is placed in the suborder Polypodiineae. Alternatively, it may be treated as the subfamily Tectarioideae of a very broadly defined family Polypodiaceae sensu lato. The family comprises seven genera, of which Tectaria is by far the largest.
Helminthostachys zeylanica is a terrestrial, herbaceous fern of southeastern Asia and Australia, commonly known as kamraj and tunjuk-langit. The species is like the other members of its family, it has clusters of sporangia on stems of fertile, spike-like fronds.
Tectaria cicutaria, the button fern, is a species of fern in the family Tectariaceae, native to the Antilles. It has thin, soft, triangular fronds up to about 3.5 feet in length; blades are once- or twice-pinnate with the final segments pinnately-lobed. The rhizome is short and erect.
The fern genus Leptopteris is a small group of plants found growing in the Pacific Islands, New Guinea and Australia. They are similar to ferns in the related genus Todea, and were originally included in that genus. However, the very thin fronds of Leptopteris differ from the thick leathery fronds of Todea, and the genera are considered distinct. A probable extinct species, Leptopteris estipularis is known from the Early Cretaceous of India.
Tectaria estremerana is a rare species of fern known by the common name Puerto Rico halberd fern. It is endemic to Puerto Rico. It is a federally listed endangered species of the United States.
Lygodium japonicum is a species of fern that is known by the common names vine-like fern and Japanese climbing fern. It is native to eastern Asia, including Taiwan, Japan, Korea, southeastern Asia, and India, and eastern Australia. The fern is present in the southeastern United States and Puerto Rico as an introduced species.
Aglaomorpha quercifolia, commonly known as the oakleaf fern or oakleaf basket fern, is a species of Aglaomorpha in the family Polypodiaceae. Other common names for the fern are pakpak lawin, gurar, koi hin, ashvakatri, kabkab, kabkaban, or uphatkarul.
Tectaria gemmifera, the snail fern, is a species of fern in the family Tectariaceae. It is native to Africa from the equator southwards, and is present in the DRC, Uganda, Kenya, Tanzania, Rwanda, Burundi, Angola, Zambia, Malawi, Mozambique, Zimbabwe, South Africa and Madagascar. Its natural habitat is deeply shaded forest floors of moist subtropical or tropical forest, and it occurs from 600 to 2,550 metres above sea level. The Latin name refers to the gemma that are produced by the fronds of this species.
Malaifilix is a genus of ferns in the family Tectariaceae, with a single species Malaifilix grandidentata, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I).
