# 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.
| Phylogeny of Danaea | Unassigned species: |
| (Danaea) D. erecta Tuomisto & R.C.Moran D. cartilaginea Christenh. & Tuomisto D. nigrescens Jenman D. kalevala Christenh. D. longicaudata Tuomisto D. grandifolia Underw. D. leussinkiana Christenh. D. nodosa (von Linné) Sm. (Arthrodanaea) D. simplicifolia Rudge D. leprieurii Kunze D. bipinnata Tuomisto D. polymorpha Lepr. ex Baker D. antillensis Christenh. D. trifoliata Reichenb. D. arbuscula Christenh. & Tuomisto D. geniculata Raddi (Holodanaea) D. acuminata Tuomisto & R.C.Moran D. falcata Tuomisto & R.C.Moran D. vivax Christenh. & Tuomisto D. alata Sm. D. oblanceolata Stolze D. wendlandii Reichenb.f. D. trichomanoides Spruce ex T.Moore D. carillensis H.Christ D. crispa Endrés D. x plicata H.Christ (D. carillensis × D. crispa) D. jenmanii Underw. D. moritziana C.Presl D. mazeana Underw. D. urbanii Maxon | Danaea alansmithii Tuomisto & Keskiniva Danaea atlantica Christenh., E.M.Almeida & L.P.Felix Danaea betancurii Rojas Danaea bicolor Tuomisto & R.C.Moran †Danaea borealis Pabst Danaea chococola Christenh. †Danaea coloradensis Knowlton, 1923 Danaea danaepinna Christenh. Danaea draco Christenh. Danaea epilithica Rojas Danaea epiphytica Christenh. Danaea excurrens Rosenst. †Danaea humiliopsis Kuzitchkina Danaea humilis T.Moore Danaea imbricata Tuomisto & R.C.Moran Danaea inaequilatera Rojas Danaea × jamaicensis Underw. (D. jenmanii × D. mazeana) Danaea latipinna Tuomisto & R.C.Moran ?Danaea lingua-cervina Christenh. & Tuomisto Danaea lucens Rojas Danaea media Liebmann Danaea megaphylla Rojas †Danaea microphylla Raciborski nom. nud. Danaea moralesiana Rojas Danaea quebradensis Christenh. Danaea riparia Christenh. & Tuomisto Danaea sellowiana C.Presl Danaea tenera C.V.Morton Danaea tuomistoana Rojas †Danaea triassica Faddeeva Danaea trinitatensis Christenh. & Tuomisto Danaea ulei H.Christ Danaea ushana Christenh. Danaea xenium Christenh. & Tuomisto Danaea ypori Christenh. Danaea zamiopsis Christenh. & Tuomisto |