Diplazium
Encyclopedia
Diplazium is a genus
of the cliff fern family that specifically includes the approximately 400 known species of twinsorus ferns. The Greek root is diplazein meaning double: the indusia in this genus lie on both sides of the vein. These ferns were earlier considered part of either the Athyriaceae, Dryopteridaceae, Aspleniaceae, or Polypodiaceae families but are often recognized as belonging to their own taxonomic family. The taxonomy of the genus is difficult and poorly-known, and by 2009 has never been the subject of a complete monographic study. Their distribution is pantropical
, with a few species extending into temperate areas.
The rhizome
of the Diplazium genus varies from creeping to erect, and is scaly. Its fronds are deciduous
or evergreen
, are trophopodicThe trophopod is food storage organ described from a number of North American ferns. It consists of the enlarged and modified leaf base filled with starch storage tissue. See W. H. Wagner, Jr. and D. M. Johnson, Taxon, Vol. 32, No. 2 (May, 1983), pp. 268-269 for more information on this organ. and are either monomorphic or weakly dimorphic
. The stipe
is green, deeply grooved from above, and is either scaly or glabrous. It always has two lunate
vascular bundles. The blades are either singular or in sets of two and are entirely pinnate
, range from oblong-lanceolate
to deltate
, and from herbaceous
to papery. It has linear basal sori
that are paired back-to-back on the same vein. The indusium is linear and persistent, and the sporangia are brownish. The USDA symbol for the species is DISPLA2. Its ITIS Taxonomic Serial Number
is 17501.
Some common varieties include Diplazium hymenodes, the peacock fern; Diplazium pycnocarpon, the glade fern or narrow-leaved spleenwort; Diplazium esculentum, the vegetable fern; Diplazium molokaiense, the Molokai twinsorus fern; and Diplazium lonchophyllum, the lance-leaved glade fern.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of the cliff fern family that specifically includes the approximately 400 known species of twinsorus ferns. The Greek root is diplazein meaning double: the indusia in this genus lie on both sides of the vein. These ferns were earlier considered part of either the Athyriaceae, Dryopteridaceae, Aspleniaceae, or Polypodiaceae families but are often recognized as belonging to their own taxonomic family. The taxonomy of the genus is difficult and poorly-known, and by 2009 has never been the subject of a complete monographic study. Their distribution is pantropical
Pantropical
In biogeography, a pantropical distribution one which covers tropical regions of all of the major continents, i.e. in Africa, in Asia and in the Americas. Examples include the plant genera Acacia and Bacopa....
, with a few species extending into temperate areas.
The rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
of the Diplazium genus varies from creeping to erect, and is scaly. Its fronds are deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
or evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
, are trophopodicThe trophopod is food storage organ described from a number of North American ferns. It consists of the enlarged and modified leaf base filled with starch storage tissue. See W. H. Wagner, Jr. and D. M. Johnson, Taxon, Vol. 32, No. 2 (May, 1983), pp. 268-269 for more information on this organ. and are either monomorphic or weakly dimorphic
Frond dimorphism
Frond dimorphism refers to a difference in ferns between the fertile and sterile fronds. Since ferns, unlike flowering plants, bear spores on the leaf blade itself, this may affect the form of the frond itself...
. The stipe
Stipe (botany)
In botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described....
is green, deeply grooved from above, and is either scaly or glabrous. It always has two lunate
Lunate
Lunate is a term meaning crescent or moon-shaped. In the specialized terminology of lithic reduction, a lunate flake is a small, crescent-shaped flake removed from a stone tool during the process of pressure flaking....
vascular bundles. The blades are either singular or in sets of two and are entirely pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
, range from oblong-lanceolate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
to deltate
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
, and from herbaceous
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
to papery. It has linear basal sori
Sorum
Sorum is a 2001 South Korean horror film and the feature film debut of director Yoon Jong-chan. Starring Kim Myeong-min and Jang Jin-young, it tells the story of a young taxi driver who moves into a dilapidated old apartment building, the site of a brutal tragedy thirty years earlier...
that are paired back-to-back on the same vein. The indusium is linear and persistent, and the sporangia are brownish. The USDA symbol for the species is DISPLA2. Its ITIS Taxonomic Serial Number
Integrated Taxonomic Information System
The Integrated Taxonomic Information System is a partnership designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagency group within the U.S...
is 17501.
Some common varieties include Diplazium hymenodes, the peacock fern; Diplazium pycnocarpon, the glade fern or narrow-leaved spleenwort; Diplazium esculentum, the vegetable fern; Diplazium molokaiense, the Molokai twinsorus fern; and Diplazium lonchophyllum, the lance-leaved glade fern.
Selected Species
- Diplazium australeDiplazium australeDiplazium australe is a small fern occurring in eastern Australia, New Zealand and Norfolk Island. The habitat is moist shaded areas, often occurring in rainforest. The common name is Austral Lady Fern....
- Diplazium dietrichianumDiplazium dietrichianumDiplazium dietrichianum is a small fern occurring in eastern Australia. It occurs in shady damp places....
- Diplazium esculentum
- Diplazium melanochlamysDiplazium melanochlamysDiplazium melanochlamys is a ground fern only found on Lord Howe Island. A common plant growing in forest. Most often seen on the southern half of the island. It can be seen between sea level and the summits of Mount Gower and Mount Lidgbird....
- Diplazium molokaienseDiplazium molokaienseDiplazium molokaiense is a rare species of fern known by the common name Molokai twinsorus fern. It is endemic to Hawaii, where it is one of the rarest ferns. It has historically been found on the islands of Kauai, Oahu, Lanai, Molokai, and Maui, but it is thought to have been extirpated from four...
- Diplazium pycnocarponDiplazium pycnocarpon-Description:Diplazium pycnocarpon ' is a tall slender-leaved fern growing as individuals with 5 to 6 leaves. The plant spreads by creeping underground stems allowing a small colony to develop over time. The leaf blade is oblong-lanceolate and once-pinnate, unlike the closely related Athyrium...
- Diplazium sibiricumDiplazium sibiricumDiplazium sibiricum is a species of fern. It is found in Siberia, across Russia, in Finland, and in northern Asia.-References:* Hardy Fern Library* Korean Plant Names Index...