Protected Native Ferns
There are six species of ferns listed under the Bermuda Protected Species Act. Two of these are endemic ferns, and the other four are native ferns described below.
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.
Bermuda Cave Fern
Ten Day or Leatherleaf Fern (Rumohra adiantiformis)
Ten Day Fern has glossy, hairless, triangular shaped fronds. The fronds are tough, so it is also known as Leatherleaf Fern. The lobed leaflets that make up the frond (the pinnae) are broadly spaced along the central stem of the frond, known as the rachis. In this species, the rachis is grooved and has scales. The fronds are spaced along a scaly rhizome that creeps along the surface of the soil. This fern grows well in full sun or shade in moist soil.
Ferns do not produce flowers and fruit, instead they reproduce from spores. In the Ten Day Fern the spores are large, round and dark. They are found in a double row on the underside of the fronds.
Ten Day Fern is native to Bermuda, and has a very wide global distribution. Its tough fronds are often used in flower arrangements as it is robust and can tolerate drying (it is said to last ten days when not in water). These characteristics have lead to wide cultivation of this fern for use in gardens and by florists; locally, however, it has become rare. In 1918 Britton noted that in Bermuda it could be found in Devonshire Marsh and Walsingham. Today it is only found in the freshwater marsh habitat in Devonshire Marsh, where only 3 or 4 specimens are thought to remain (Fern Recovery Plan). Ten Day Fern is therefore listed as locally Critically Endangered under the Protected Species Act 2003 (Protected Species Order 2007).
Long Spleenwort (Asplenium heterochroum)
Long Spleenwort is a fern-like plant that grows in damp, shaded rocky habitats, such as around caves and in rocky woodland. It is also known to grow out of man-made structures made of stone. Also known as the Bicoloured Spleenwort, this species is native to Bermuda, as well as the Caribbean, Southern United States, Mexico and Central America.
Long Spleenwort grow from a Bermuda stone chimney
The leaves of Long Spleenwort can grow up to 16 inches long. Each leaf blade is about an inch wide with 20-40 pairs of pinnae (leaflets on a fern). The pinnae have toothed edges and grow opposite each other on a black central stem. These tough stems sometimes remain on the plant after the bright green leaves have dropped off. The reproductive structures are linear spores held on the underside of the pinnae on mature leaf blades.
Britton described the Long Spleenwort as common island-wide on walls, cliffs and shaded rocks. Today it may still be distributed island-wide, but is rarely seen. Due to its significant decline, this native species is listed under the Protected Species Act 2003 (Protected Species Order 2007).
Spores of Long Spleenwort
Toothed Spleenwort (Asplenium trichomanes-dentatum)
Formerly known as Asplenium dentatum, the Toothed Spleenwort is native to Bermuda, Florida, the Caribbean, Mexico and Central America.
Leaf blades are up to 3 inches long with 6-8 pairs of pinnae. Pinnae medium green, are irregularly shaped and have slightly toothed margins. The rachis is green with no scales or hairs. The spores of this spleenwort are found in rows on the underside of the pinnae on fertile leaf blades.
Britton records the distribution of this small fern as occurring on Abbot’s Cliff and on shaded rocks around caves in the Walsingham area, and on islands in the Great Sound. Its current distribution is unknown, but it can be found in the nature reserves at Walsingham. Due to its past population decline, Toothed Spleenwort has been listed under the Bermuda Protected Species Act 2003 (Protected Species Order 2007).
Protected Species Photo Gallery
Learn More:
- Protected Species Page
- 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).
