Treefern

Cyathea is a genus of tree ferns, the type genus of the fern order Cyatheales.

The genus name Cyathea is derived from the Greek kyatheion, meaning "little cup", and refers to the cup-shaped sori on the underside of the fronds.

Description

The species of Cyathea are mostly terrestrial ferns, usually with a single tall stem. Rarely, the trunk may be branched or creeping. Many species also develop a fibrous mass of roots at the base of the trunk.

The genus has a pantropical distribution, with over 470 species. They grow in habitats ranging from tropical rain forests to temperate woodlands.

Classification

Conant et al. in 1996, concluded on molecular cpDNA and morphological evidence that a system of three clades – Alsophila, Cyathea and Sphaeropteris was the most accurate reflection of evolutionary lineages within the Cyatheaceae, Alsophila being the most basal and Cyathea and Sphaeropteris derived sister groups.^[1] In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), these are accepted as separate genera, Alsophila, Cyathea and Sphaeropteris.^[2] Cnemidaria Presl, 1836 is a junior synonym or redundant subset.^[3][4]

Species

As of July 2021, World Ferns (Version 12.3) accepted the following species:^[5]

Extinct species

Eocene Cyathea inequilateralis Chuckanut Formation, Washington

• †Cyathea cranhamii
• †Cyathea inequilateralis - Eocene, North American west coast

References

Dried Cyathea podophylla.

Notes

Bibliography

• Christenhusz, M.J.M. (2009). New combinations and an overview of Cyathea subg. Hymenophyllopsis (Cyatheaceae). Phytotaxa 1: 37–42.
• Large, M.F. and J.E. Braggins (2004). Tree Ferns. Timber Press, Inc. ISBN 0-88192-630-2
• Lehnert, M. (2006). New species and records of tree ferns (Cyatheaceae, Pteridophyta) in the northern Andes. Organisms, Diversity & Evolution 6: 321–322, electronic supplement 13: 1–11.
• Lehnert, M. (2009). Three new species of scaly tree ferns (Cyathea-Cyatheaceae) from the northern Andes. Phytotaxa 2: 43–56.
• The International Plant Names Index