Danaea

Danaea is a fern genus of approximately 50 species in the eusporangiate fern family Marattiaceae. They are small to intermediately large ferns with erect or creeping rhizomes and usually once-pinnate leaves with opposite pinnae. The fertile leaves are contracted, acrostichoid and covered below with sunken, linear synangia. The genus Danaea has a neotropical distribution, occurring from southern Mexico through Central America, the Caribbean and northern South America to Bolivia, Paraguay and the Mata Atlantica in Brazil and Northern Argentina. There is also a population on Isla del Coco (Cocos Island) in the Pacific.

The genus name of Danaea is named after the Greek mythology, Danaë, an Argive princess and mother of the hero Perseus by Zeus.

Two species Danaea carillensis (Costa Rica) and D. simplicifolia (Guianas, Brazil, Trinidad) have simple, undivided leaves, and some other species sometimes have bipinnate leaves (D. atlantica, D. bipinnata, D. nodosa, D. urbanii). One species Danaea kalevala of the Lesser Antilles was named in honour of the Finnish heroic epic Kalevala.

The basal chromosome number for this genus is 2n=80. The type species is Danaea nodosa.

Taxonomy
Danaea is the basal lineage in the Marattiaceae and the oldest fossils are from the Paleocene, a period where rainforests became more abundant. It has radiated in these early rainforests and presently counts about 50 species in 3 sections: sect. Danaea, sect. Arthrodanaea and sect. Holodanaea.

Species

 * Danaea acuminata Tuomisto & R.C.Moran
 * Danaea alata Sm.
 * Danaea antillensis Christenh.
 * Danaea atlantica Christenh., E.M.Almeida & L.P.Felix
 * Danaea arbuscula Christenh. & Tuomisto
 * Danaea bicolor Tuomisto & R.C.Moran
 * Danaea bipinnata Tuomisto
 * †Danaea borealis Pabst
 * Danaea carillensis H.Christ
 * Danaea cartilaginea Christenh. & Tuomisto
 * Danaea chococola Christenh.
 * Danaea crispa Endrés
 * Danaea danaëpinna Christenh.
 * Danaea draco Christenh.
 * Danaea epiphytica Christenh.
 * Danaea erecta Tuomisto & R.C.Moran
 * Danaea excurrens Rosenst.
 * Danaea falcata Tuomisto & R.C.Moran
 * Danaea geniculata Raddi
 * Danaea grandifolia Underw.
 * Danaea humilis T.Moore
 * Danaea imbricata Tuomisto & R.C.Moran
 * Danaea × jamaicensis Underw. (D. jenmanii × D. mazeana)
 * Danaea jenmanii Underw.
 * Danaea kalevala Christenh.
 * Danaea latipinna Tuomisto & R.C.Moran
 * Danaea leprieurii Kunze
 * Danaea leussinkiana Christenh.
 * Danaea lingua-cervina Christenh. & Tuomisto
 * Danaea longicaudata Tuomisto
 * Danaea mazeana Underw.
 * Danaea media Liebmann
 * Danaea moritziana C.Presl
 * Danaea nodosa Sm.
 * Danaea oblanceolata Stolze
 * Danaea × plicata H.Christ (D. carillensis × D. crispa)
 * Danaea polymorpha Lepr. ex Baker
 * Danaea quebradensis Christenh.
 * Danaea riparia Christenh. & Tuomisto
 * Danaea sellowiana C.Presl
 * Danaea simplicifolia Rudge
 * Danaea tenera C.V.Morton
 * Danaea trichomanoides Spruce ex T.Moore
 * Danaea trifoliata Reichenb.
 * Danaea trinitatensis Christenh. & Tuomisto
 * Danaea ulei H.Christ
 * Danaea urbanii Maxon
 * Danaea ushana Christenh.
 * Danaea vivax Christenh. & Tuomisto
 * Danaea xenium Christenh. & Tuomisto
 * Danaea ypori Christenh.
 * Danaea wendlandii Reichenb.f.
 * Danaea zamiopsis Christenh. & Tuomisto