Xaxim

Description

Dicksonia sellowiana, the xaxim, or samambaiaçu or imperial samambaiaçu, is an arborescent fern in the family Dicksoniaceae, native to the tropical Americas. The fern is native to Southern Mexico, Central America, and South America. In the South American Atlantic Forest biome, it is found in: Southeastern Brazil within in the states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul; in northeast of Argentina within Misiones Province; and within eastern Paraguay. Dicksonia sellowiana has an erect and cylindrical caudex, reaching sometimes more than 10 metres (33 ft) high, the fronds are bipinnate and 2 m (6 ft 7 in) long. Due to illegal extraction, the species is at risk of extinction. Dicksonia is a genus of tree ferns in the order Cyatheales. It is regarded as related to Cyathea, but is considered to retain more primitive traits, dating back at least to the Jurassic and Cretaceous periods. The fossil record includes stems, pinnules, and spores. The genus contains 20–25 species, distributed from Mexico to Argentina, Brazil, Uruguay and Chile, St. Helena, New Zealand, New Caledonia, Australia, Indonesia, New Guinea, and the Philippines. New Guinea has the greatest diversity, with five species. The genus was first described by Charles Louis L'Héritier de Brutelle in 1788. The name honors James Dickson, a prominent nurseryman and botanist.