Hemidictyum is a genus of ferns with a single species, Hemidictyum marginatum, commonly known as the marginated half net fern.[ In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only genus in the family Hemidictyaceae.][ Alternatively, the family, along with Aspleniaceae Sensu, may be placed in a much more broadly defined family Aspleniaceae as the subfamily Asplenioideae.][
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Taxonomy
The name Hemidictyum was derived from the terms hemi (half) and diktyon (net), from the veins being netted only half-way across the pinnules.[ The Fern Manual, being a description of all the best stove, greenhouse and hardy ferns by contributors to the Journal of Horticulture p.69, London, 1863]
Phylogenetic relationships
Hemidictyaceae is considered to be a sister family to Aspleniaceae s.l., believed to have diverged during the Cretaceous period.[ The following cladogram for the suborder Aspleniineae (as eupolypods II), based on Lehtonen (2011),][ and Rothfels & al. (2012),][ shows a likely phylogenetics relationship between the Hemidictyaceae and the other families of the clade.
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Species
There is currently only one accepted Hemidictyum species, Hemidictyum marginatum.[
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Distribution
Hemidictyum is a native neotropical fern, found in Mexico, the Caribbean, Costa Rica, Guatemala, Honduras, Nicaragua, Panama, French Guiana, Suriname, Brazil, Venezuela, Puerto Rico, Bolivia, Colombia, Ecuador, and Peru.[
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