Culcita is a small genus of ferns comprising just two accepted species, Culcita coniifolia and Culcita macrocarpa. It is placed in its own family, Culcitaceae, within the order Cyatheales in the Pteridophyte Phylogeny Group classification (PPG I, 2016); Plants of the World Online instead treats it more narrowly, as the subfamily Culcitoideae within a broadly circumscribed family Cyatheaceae. The genus authorship, per GBIF, is credited to C.Presl.
The genus has a notably disjunct distribution spanning the Americas and Macaronesia/Iberia. Culcita coniifolia occurs across the Caribbean, Central America, and the northern part of South America. Culcita macrocarpa — the better-known and more geographically restricted of the two — is native to Macaronesia (most of the Azores, Madeira, and Tenerife in the Canary Islands), with additional, possibly introduced, occurrences on the Iberian Peninsula in northern Spain and Portugal.
Known as the woolly tree fern, Culcita macrocarpa is a large plant, with fronds reaching up to 2 metres and rhizomes thickly coated in long, silky, light-brown hairs that give the species its common name. It is the only member of the order Cyatheales native to Europe. It grows on siliceous rocky slopes in shaded, humid valleys and near waterfalls or streams, typically under evergreen forest up to about 1,100 metres elevation, and it avoids limestone substrates, requiring shade, warmth, and high atmospheric humidity throughout the year.
The species is locally threatened: conversion of native forest into plantations has reduced its habitat, and in mainland Portugal it is classified as critically endangered, with fire and eucalyptus-plantation-driven soil desiccation cited as the main pressures on remaining populations. Its lesser-known sister species, Culcita coniifolia, is much more widespread across the American tropics but far less documented in general reference sources.
Distribution
Culcita is disjunctly distributed: Culcita coniifolia occurs across the Caribbean, Central America, and northern South America, while Culcita macrocarpa is native to Macaronesia (Azores, Madeira, Canary Islands) with additional, possibly introduced, populations on the Iberian Peninsula in northern Spain and Portugal.
Ecology
Culcita macrocarpa grows on siliceous rocky slopes in deep, shaded valleys and near waterfalls or streams that provide constant moisture, usually under evergreen forest up to about 1,100 m elevation. It avoids limestone substrates and requires shade, warmth, and high atmospheric humidity year-round.
Conservation
Culcita macrocarpa is threatened by the conversion of forests into plantations. In mainland Portugal it is classified as critically endangered, where fire is the main threat and eucalyptus plantations cause soil desiccation that prevents the species from regenerating.
Taxonomy Notes
Culcita is the sole genus of family Culcitaceae under the 2016 Pteridophyte Phylogeny Group classification (PPG I), placed in order Cyatheales — the placement GBIF's backbone also follows, crediting authorship to C.Presl. Plants of the World Online instead treats it as subfamily Culcitoideae within a broadly defined family Cyatheaceae (as of November 2019).
