Bermuda Cave Fern (Ctenitis sloanei)

This fern was at one time known as Dryopteris speluncae, and was thought to be endemic to Bermuda (Britton, 1918). Bermuda Cave Fern is now recognised as a Bermudian population of Ctenitis sloanei (Fern Recovery Plan). Ctenitis sloanei is native to Bermuda where it is known as Bermuda Cave Fern, and also Florida, the Caribbean, Mexico, Central America and Northwestern South America. Outside Bermuda, this species is called Florida Tree Fern, Red Hair Comb Fern or Florida Lace Fern. It is listed as endangered in Florida. 

Bermuda Cave Fern has large fronds up to 3 feet (90cm) long and 3 feet wide. The pinnae (leaflets which make up one frond) are divided 2 or 3 times. The stems of the fronds are covered by hairs. This large fern grows up from the soil more often than of out of crevices in rocks like other cave ferns. It grows well in organic rich soils in lightly shaded locations where it is sheltered from wind and salt spray.

The distribution of this fern in the early 1900s is described by Britton as occurring in “caves, holes and ledges between Harrington Sound and Castle Harbour.” Today, this species has become very rare in Bermuda due to destruction of its habitat by development and invasive plants. It is listed under the Bermuda Protected Species Act 2003 (Protected Species Order 2007) as Critically Endangered.

Learn More:

• Protected Species Information Sheet for Bermuda Cave Fern [PDF]

• The Flora of Bermuda by Nathaniel Lord Britton in 1918. (Available in the BAMZ library).

• Recovery Plan for Six Fern Species from Bermuda (2010, Dept. of Conservation Services).

• Copeland, Alison I. 2021. Observations of the native plants protected by the Bermuda Protected Species Act 2003 during the period 2013 - 2020. Technical Report of the Biodiversity Section, Department of Environment and Natural Resources, Government of Bermuda. Flatts, Bermuda. 106 pages.