Dicranopteris is placed in the homosporous family Gleicheniacea, commonly known as the ‘Forked Fern'. Dicranopteris is derived from the Greek words dikranos and pteris, meaning 'two headed' and 'fern' respectively. This term relates to the way the blades dichotomously branch. This genus currently recognizes 12 species, only one of which (Dicranopteris linearis) occurs in Australia. Dicranopteris linearis occupies peaty sand or rocky habitats, usually condensing into thickets that are 2-3 meters high (Chinnock & Bell, 1998).
Dicranopteris linearis is not threatened in Australia.
Dicranopteris are perennial ferns that live on land or rocky surfaces. Rhizomes are long and creep along the surface; covered by protective layer of branched, multicellular hairs that are divided internally by septa; roots form longitudinally along the rhizome. The stalks of the fronds are scattered. Fronds erect or climbing; fronds dividing into 1-many tiers of opposite, primary branches of equal or unequal length; dormant vegetative buds forming between primary branches; buds containing leaf or shoots that are not yet fully developed are protected by pinnules; blades are oval in shape with a tapered point and have two rows of pinnules; a pair of deflexed accessory branches present on ultimate fork of frond, approximately 3-6mm above fork. One species (Dicranopteris linearis var altissima, exclusive to Queensland) displays unusual morphology, additional accessory branches may be present on the rachis at the ultimate fork (including lamina like that of the penultimate segments). This morphological feature does not occur in Western Australian members. Ultimate segments entire. The arrangement of veins in lamina is open and dichotomously divided; ultimate vein is forked at least twice. Clusters of sporangia (usually 5-15) form in two rows either side of the midrib, they are circular in shape. At least one cluster of sporangia is located at each ultimate vein group; sporangia remain separate from paraphyses. Spores form trilete and tetrahedral groups.
A link to the species page within Flora Base of Western Australia: - See https://florabase.dpaw.wa.gov.au/browse/profile/17654
A link to the species page within Flora of Australia online: -See http://www.anbg.gov.au/abrs/online-resources/flora/stddisplay.xsql
Morphological variation exists between Dicranopteris linearis var linearis (found in Western Australia) and Dicranopteris linearis var altissima (restricted to north-east Queensland. Dicranopteris linearis var altissima has an unusual morphology, with extra laminas above the last fork of the rachis. This characteristic does not occur in the Western Australian species (Chinnock & Bell, 1998).
Dicranopteris linearis is commonly known as the 'forking fern' due to the way the in which the blades pseudo-dichotomously branch (Spooner, 1997).This particular species is relatively persistent in the environment due to its ability to thrive in nutrient-depleted soils.
Dicranopteris fall into one of the largest groups of living ferns known as Leptosporangiates. Leptosporangiate ferns constitute the class Pteridopsida or Polypodiopsida. Dicranopteris are considered Leptosporangiate ferns because their sporangia arise from a single epidermal cell as opposed to the Eusporangiate ferns thats sporangia form from a group of cells. According to the classification scheme proposed by Smith et al (2006) and Christenhusz et al (2011), Leptosporangiates diverged from their sister clades including horsetails and marratioids rapidly during the Paleozoic era (Schuettpeltz & Pryer, 2008).
Leptosporangiates constitute a well supported monophyletic group, including the gleichenioid ferns. Glechenioid ferns including Dicranopteris are characterized by sporangia that develop from a single cell, mature walls and an annulus that serves to eject the spores (Schuettpeltz & Pryer, 2008).
Kingdom: Plantae
Phylum/Division: Filicophyta
Class: Pteridopsida
Order: Gleicheniales
Family: Gleicheniaceae
Genus: Dicranopteris
Species: D. linearis
For Phylogeny and Description see: http://137.132.71.21/dna/organisms/details/417
Dicranopteris can be found across pantropical and temperate regions of Australasia and New Caledonia. Despite being a tropical fern, Dicranopteris has also been found in semi-arid to arid regions including central Australia, Africa, Asia, Polynesia and New Zealand.
In Western Australia, Dicranopteris linearis is distributed throughout the Northern Province including central Kimberley, Ord Victoria Plain, Victoria Bonaparte. Local government areas (LGA's) include Halls Creek and Wyndhman East-Kimberley.
For Dicranopteris linearis' distribution throughout Western Australia see: https://florabase.dpaw.wa.gov.au/browse/map/20891
Dicranopteris are terrestrial ferns that occupy peaty sand or rocky habitats. The tropical fern is commonly found in marginal areas of forests, open hillsides and road cuttings. Dicranopteris linearis colonize into dense thickets (3 meters deep) and usually spreads over small shrubs, climbing over taller vegetation (Spooner 1997; Chinnock & Bell, 1998)
Dicranopteris linearis is given the common name 'Resam' in countries such as Malaysia, Singapore and New Guinea. In New Guinea, the vines are used to attach posts together when constructing houses. The fronds may be used as personal decorations for special ceremonies. They may also be woven into decorative arm and waistbands. Dicranopteris linearis may also be used to treat intestinal worms as well as boils, ulcers and wounds.
In Malaysia, the leaves are crushed and can be used as poultice to control fever (Ria Tan, 2001).
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