Cyatheales - Definition and Overview

Tree Ferns (Cytheales)
Australian tree fern
Scientific classification
Domain: Eukaryota Kingdom: Plantae Division: Pteridophyta Order: Cytheales
Families and Genera
Cytheaceae     Alsophila     Cnemidaria     Cythaea     Sphaeropteris     Trichipteris Dicksoniaceae     Calochlaena     Cibotium     Culcita     Cystodium     Dicksonia     Thyrsopteris Losophoriaceae     Lophosoria Loxomaceae     Loxoma     Loxsomopsis Metaxyaceae     Metaxya

The Order Cytheales is a taxonomic division of the fern (Division Pteridophyta) subclass, Cyatheatae, which includes the tree ferns. The Australian Tree Fern (Cythaea australis) and Tasmanian Tree Fern (Dicksonia antarctica) may be the best known species of Cytheales, as these species are widely grown as garden plants in tropical, subtropical, and mild temperate climates.

The families that constitute Cytheales have been relatively firmly established as a monophyletic clade by DNA sequencing and morphological studies. The Order Plagiogyriales, which contains the Family Plagiogyriaceae, is most closely related to the Cytheales, not to the Osmundales as had been previously supposed.

Reference:

• Pryer, K.M., A.R. Smith, and J.E. Skog. 1995. Phylogenetic relationships of extant ferns based on evidence from morphology and rbcL sequences. American Fern Journal 85: 205-282.