Cyatheales
Order Cyatheales
This order includes many ferns that we call "tree ferns". The rhizome grows vertically to form a trunk of this tree-like plant. There is no wood inside these fern trunks, but some can grow up to 33 ft tall. A tree-like habit has evolved in plants, and specifically ferns several times.
Diversity
8 families (Cibotiaceae, Culcitaceae, Cyatheaceae, Dicksoniaceae, Loxsomataceae, Metaxyaceae, Plagiogyriaceae, and Thyrsopteridaceae); 13 genera; ~700 species
Geologic Range
Jurassic - present
Cibotiaceae
1 genus (Cibotium) with 11 species
Tropical tree ferns found in Hawaiʻi, Southeast Asia, and the cloud forests of Central America and Mexico
Stems
Ferns have a single, erect trunk-like rhizome, 7-35 feet tall with a diameter up to 3 ft
Leaves
Large compound fronds can grow up to 12 ft
The fronds are singularly divided but divide at the end where the spores form
Reproductive features
Sporangia produced on the underside of fronds
Gametophyte
?
Above: Cibotium menziesii n Hawai'i
Culcitaceae
1 genus (Culcita) with 2 species (C. coniifolia; C. macrocarpa)
Ferns native to the Americas, Macaronesia, and the Iberian Peninsula
Stems
Large upright rhizome serves as the trunk and can reach up to 7 ft in height
Rhizomes are thickly coated with long silky, light brown hairs
Leaves
Large compound fronds with long stipes
Reproductive features
?
Gametophyte
?
Above: Culcita macrocarpa
Cyatheaceae
3 extant genera (Alsophila, Cyathea, and Sphaeropteris) with 643 species
This family includes the world's tallest tree ferns, which reach heights up to 20 m
Late Jurassic - present
Stems
Ferns have a single, erect trunk-like rhizome
Leaves
Fronds reaching 3–4 m in length, and have a final crown width of some 6 m
The fronds are circinate before unfolding and usually pinnately or bipinnately compound, with deeply pinnately lobed leaflets
The large leaves are covered in scales and hairs
Reproductive features
Sori are often covered by an indusium; these can be cup-shaped (cyatheoid), hood-shaped (hemitelioid), enclosing the sorus (sphaeropteroid), or scaly
Gametophyte
?
Above: Cyathea glauca, endemic species of Réunion Island
Dicksoniaceae
3 extant genera (Calochlaena, Dicksonia, and Lophosoria) with 20–25 species,
Large tree ferns, as well as smaller epiphytic ferns
Ferns from tropical regions in the Southern Hemisphere, distributed from Mexico to Argentina, Brazil, Uruguay and Chile, St. Helena, New Zealand, New Caledonia, Australia, Indonesia, New Guinea, and the Philippines
Early Cretaceous - present
Stems
?
Leaves
Large pinnate fronds, 1–4 m long
Reproductive features
?
Gametophyte
?
Above: Dicksonia antarctica
Loxsomataceae
2 extant genera/species (Loxsoma cunninghamii and Loxsomopsis pearcei )
Loxsoma is found in New Zealand, and Loxsomopsis from Costa Rica and South America
Jurassic - present (fossils from North America, India and Japan)
Stems
?
Leaves
Leaves that can be as long as 16 ft long
Reproductive features
?
Gametophyte
?
Above: Loxsoma cunninghamii in New Zealand
Metaxyaceae
1 genus (Metaxya) with 5 species
Ferns from Central and South America
Stems
?
Leaves
Large fronds that approach 8 ft (2.5 m) in length
Reproductive features
?
Gametophyte
?
Above: Metaxya rostrata in Bahia, Brazil
Plagiogyriaceae
1 genus (Plagiogyria) with 12 species
Ferns that grow in forest soils in mountainous areas of tropical and subtropical regions
Most are native to Asia; one is found in the Americas
Stems
?
Leaves
?
Reproductive features
?
Gametophyte
?
Above: Plagiogyria egenolfioides
Thyrsopteridaceae
1 extant species (Thyrsopteris elegans)
This plant is endemic to the Juan Fernandez Archipelago off the coast of Chile
Cretaceous (Cenomannian) - present
Stems
?
Leaves
?
Reproductive features
?
Gametophyte
?
Above: Thyrsopteris elegans
Additional Resources
Fern can reanimate its dead leaves to act like roots (BGR 4Feb2024)