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 in the Pacific.
Two species Danaea carillensis and D. simplicifolia have simple, undivided leaves, and some other species sometimes have bipinnate leaves. 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