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. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), these are accepted as separate genera, Alsophila, Cyathea and Sphaeropteris. Cnemidaria Presl, 1836 is a junior synonym or redundant subset. Species , World Ferns (Version 12.3) accepted the following species: Cyathea abbreviata I.Fernald Cyathea abrapatriciana Lehnert & A.Tejedor Cyathea acantha (Sehnem) Lehnert Cyathea acutidens (Christ) Domin Cyathea aemula Lehnert Cyathea affinis (G.Forst.) Sw. Cyathea akawaiorum P.J.Edwards Cyathea alata (E.Fourn.) Copel. Cyathea alatissima (Stolze) Lehnert Cyathea alfonsiana L.D.Gómez Cyathea alsophiloides S.Maciel & Lehnert Cyathea alstonii R.M.Tryon Cyathea amabilis (C.V.Morton) Lehnert Cyathea andaquiensis Lehnert, F.Giraldo & W.Rodríguez Cyathea andicola Domin Cyathea andina (H.Karst.) Domin Cyathea angelica A.Tejedor & G.Calat. Cyathea antioquensis A.Rojas Cyathea arborea (L.) Sm. Cyathea aristata Domin Cyathea armata (Sw.) Domin Cyathea arnecornelii Lehnert Cyathea ars Lehnert Cyathea aspera (L.) Sw. Cyathea asplenioides (A.C.Sm.) Christenh. Cyathea assurgens R.M.Tryon Cyathea atahuallpa (R.M.Tryon) Lellinger Cyathea aterrima (Hook.) Domin Cyathea atrocastanea Labiak & F.B.Matos Cyathea atrovirens (Langsd. & Fisch.) Domin Cyathea aurea Klotzsch Cyathea austroamericana Domin Cyathea austropallescens Lehnert Cyathea axillaris (Raddi) Lellinger Cyathea azuayensis Sodiro Cyathea barringtonii A.R.Sm. ex Lellinger Cyathea bella (Rchb.fil. ex Mett.) Domin Cyathea bettinae Lehnert Cyathea bicrenata Liebm. Cyathea biliranensis Copel. Cyathea bipinnata (R.M.Tryon) R.C.Moran Cyathea bipinnatifida (Baker) Domin Cyathea boconensis H.Karst. Cyathea borinquena (Maxon) Domin Cyathea boryana (Kuhn) Domin Cyathea bradei (P.G.Windisch) Lellinger Cyathea brucei Lehnert Cyathea brunnescens (Barrington) R.C.Moran Cyathea calamitatis Lehnert Cyathea callejasii Lehnert, F.Giraldo & A.Tejedor Cyathea caracasana (Klotzsch) Domin Cyathea cardenasii Lehnert, F.Giraldo & W.Rodríguez Cyathea carolihenrici Lehnert Cyathea carolinae A.Tejedor & G.Calat. Cyathea catacampta Alston