Cycads are
seed plants that typically have a stout and woody (
ligneous
A woody plant is a plant that produces wood as its structural tissue and thus has a hard stem. In cold climates, woody plants further survive winter or dry season above ground, as opposite to herbaceous plants that die back to the ground until sp ...
)
trunk
Trunk may refer to:
Biology
* Trunk (anatomy), synonym for torso
* Trunk (botany), a tree's central superstructure
* Trunk of corpus callosum, in neuroanatomy
* Elephant trunk, the proboscis of an elephant
Computing
* Trunk (software), in rev ...
with a
crown of large, hard, stiff,
evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...
and (usually)
pinnate
Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, an ...
leaves. The species are
dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly and live very long. Because of their superficial resemblance, they are sometimes mistaken for
palms or
ferns, but they are not closely related to either group.
Cycads are
gymnosperms (naked-seeded), meaning their
unfertilized seeds are open to the air to be directly fertilized by
pollination
Pollination is the transfer of pollen from an Stamen, anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by Anemophily, wind. Pollinating agents can ...
, as contrasted with
angiosperms
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants ...
, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized
pollinators, usually a specific species of
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
. Both male and female cycads bear cones (
strobili), somewhat similar to
conifer cone
A conifer cone (in formal botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers ...
s.
Cycads have been reported to
fix nitrogen in association with various
cyanobacteria living in the roots (the "coralloid" roots). These photosynthetic bacteria produce a
neurotoxin called
BMAA
β-Methylamino--alanine, or BMAA, is a non-proteinogenic amino acid produced by cyanobacteria. BMAA is a neurotoxin and its potential role in various neurodegenerative disorders is the subject of scientific research.
Structure and properties ...
that is found in the
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...
s of cycads. This neurotoxin may enter a human food chain as the cycad seeds may be eaten directly as a source of flour by humans or by wild or feral animals such as bats, and humans may eat these animals. It is hypothesized that this is a source of some
neurological diseases in humans.
Other defence mechanisms against herbivores is the accumulation of toxins in seeds and vegetative tissues, and through
horizontal gene transfer they have acquired a family of genes from a microbial organism, most likely fungi, which gives them the ability to produce an insecticidal toxin.
Cycads all over the world are in decline, with four species on the brink of extinction and seven species having fewer than 100 plants left in the wild. The plant has a very long fossil history, with evidence that they existed in greater abundance and in greater diversity before the Jurassic and late Triassic
mass extinction events.
Description
Cycads have a
cylindrical trunk which usually does not
branch
A branch, sometimes called a ramus in botany, is a woody structural member connected to the central trunk of a tree (or sometimes a shrub). Large branches are known as boughs and small branches are known as twigs. The term '' twig'' usuall ...
. However, some types of cycads, such as ''Cycas zeylanica,'' can branch their trunks. The apex of the stem is protected by modified leaves called
cataphylls. Leaves grow directly from the trunk, and typically fall when older, leaving a crown of leaves at the top. The leaves grow in a
rosette form, with new foliage emerging from the top and center of the crown. The trunk may be buried, so the leaves appear to be emerging from the ground, so the plant appears to be a
basal rosette. The leaves are generally large in proportion to the trunk size, and sometimes even larger than the trunk.
The leaves are
pinnate
Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, an ...
(in the form of bird feathers,
pinnae), with a central leaf stalk from which parallel "ribs" emerge from each side of the stalk, perpendicular to it. The leaves are typically either compound (the leaf stalk has
leaflets emerging from it as "ribs"), or have edges (
margin
Margin may refer to:
Physical or graphical edges
* Margin (typography), the white space that surrounds the content of a page
*Continental margin, the zone of the ocean floor that separates the thin oceanic crust from thick continental crust
*Leaf ...
s) so deeply cut (
incised
Incision may refer to:
* Cutting, the separation of an object, into two or more portions, through the application of an acutely directed force
* A type of open wound caused by a clean, sharp-edged object such as a knife, razor, or glass splinter
* ...
) so as to appear compound. The Australian genus
Bowenia
The genus ''Bowenia'' includes two living and two fossil species of cycads in the family Stangeriaceae, sometimes placed in their own family Boweniaceae. They are entirely restricted to Australia. The two living species occur in Queensland. '' ...
and some Asian species of Cycas, like
Cycas multipinnata
''Cycas multipinnata'' (or ''Epicycas multipinnata'') is a species of cycad (faily Cycadaceae) in southwestern China and northern Vietnam. It is noteworthy for three things: First it is one of the tuberous species which some taxonomists segregate ...
,
Cycas micholitzii and
Cycas debaoensis, have leaves that are
bipinnate
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The edge of the leaf may be regular ...
, which means the leaflets each have their own subleaflets, growing in the same form on the leaflet as the leaflets grow on the stalk of the leaf (
self-similar geometry).
Confusion with palms
Due to superficial similarities in foliage and plant structure, cycads and
palms are often mistaken for each other. They also can occur in similar climates. However, they belong to different
phyla Phyla, the plural of ''phylum'', may refer to:
* Phylum, a biological taxon between Kingdom and Class
* by analogy, in linguistics, a large division of possibly related languages, or a major language family which is not subordinate to another
Phy ...
and as such are not closely related. The similar structure is the product of
convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
.
Beyond those superficial resemblances, there are a number of differences between cycads and palms. For one, both male and female cycads are
gymnosperm
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν ...
s and bear cones (strobili), while palms are
angiosperms and so flower and bear fruit. The mature foliage looks very similar between both groups, but the young emerging leaves of a cycad resemble a
fiddlehead fern before they unfold and take their place in the rosette, while the leaves of palms are just small versions of the mature frond. Another difference is in the
stem. Both plants leave some scars on the stem below the rosette where there used to be leaves, but the scars of a cycad are
helically arranged and small, while the scars of palms are a circle that wraps around the whole stem. The stems of cycads are also in general rougher and shorter than those of palms.
Taxonomy
The two extant
families of cycads all belong to the order
Cycadales, and are the
Cycadaceae
''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity i ...
and
Zamiaceae
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South Americ ...
(including
Stangeriaceae
Stangeriaceae is the smallest family of the cycads, including only two extant genera, ''Stangeria'' and '' Bowenia'', which both have an underground stem.
Taxonomy
Although the family was first published by Schimper and Schenk as Stangerieae, ...
). These cycads have changed little since the Jurassic in comparison to some other plant divisions. Five additional families belonging to the
Medullosales became extinct by the end of the Paleozoic Era.
Based on genetic studies, cycads are thought to be more closely related to ''
Ginkgo'' than other living gymnosperms. Both are thought to have diverged from each other during the early
Carboniferous.
Classification of the Cycadophyta to the rank of family.
* Class Cycadopsida
Brongniart 1843
** Order Cycadales
Persoon ex von Berchtold & Presl 1820
*** Suborder Cycadineae
Stevenson 1992
**** Family
Cycadaceae
''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity i ...
Persoon 1807
***** Genus ''
Cycas''
*** Suborder Zamiineae
Stevenson 1992
**** Family
Zamiaceae
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South Americ ...
Horaninow 1834
***** subfamily Diooideae
Pilg. 1926
****** Genus ''
Dioon''
***** subfamily Zamioideae
Stevenson 1992
****** Tribe Encephalarteae
Miquel 1861
******* Genus ''
Macrozamia
''Macrozamia'' is a genus of around forty species of cycads, family Zamiaceae, all of which are endemic to Australia. Many parts of the plant have been utilised for food and material, most of which is toxic if not processed correctly.
Descrip ...
''
******* Genus ''
Lepidozamia''
******* Genus ''
Encephalartos''
****** Tribe Zamieae
Miquel 1861
******* Genus ''
Bowenia
The genus ''Bowenia'' includes two living and two fossil species of cycads in the family Stangeriaceae, sometimes placed in their own family Boweniaceae. They are entirely restricted to Australia. The two living species occur in Queensland. '' ...
''
******* Genus ''
Ceratozamia
''Ceratozamia'' is a genus of New World cycads in the family Zamiaceae. The genus contains 27 known currently living species and one or two fossil species. Most species are endemic to mountainous areas of Mexico, while few species extend into the ...
''
******* Genus ''
Stangeria''
******* Genus ''
Zamia
''Zamia'' is a genus of cycad of the family Zamiaceae, native to North America from the United States (in Georgia and Florida) throughout the West Indies, Central America, and South America as far south as Bolivia. The genus is considered to be ...
''
******* Genus ''
Microcycas''
Fossil record
The probable former range of cycads can be inferred from their global distribution. For example, the family Stangeriaceae contains only three extant species in Africa and Australia. Diverse fossils of this family have been dated to 135 mya, indicating that diversity may have been much greater before the Jurassic and late Triassic
mass extinction events. However, the cycad fossil record is generally poor and little can be deduced about the effects of each mass extinction on their diversity.
Instead, correlations can be made between the number of extant
gymnosperms and
angiosperms
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants ...
. It is likely that cycad diversity was affected more by the great angiosperm radiation in the mid-Cretaceous than by extinctions. Very slow cambial growth was first used to define cycads, and because of this characteristic the group could not compete with the rapidly growing, relatively short-lived angiosperms, which now number over 250,000 species, compared to the 1080 remaining gymnosperms.
Origins
The cycad fossil record dates to the early
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...
, (
mya). There is controversy over older cycad fossils that date to the late
Carboniferous period, . This
clade probably diversified extensively within its first few million years, although the extent to which it radiated is unknown because relatively few fossil specimens have been found. The regions to which cycads are restricted probably indicate their former distribution in the
Pangaea supercontinent before the supercontinents
Laurasia and
Gondwana separated. Recent studies have indicated that the common perception of existing cycad species as
living fossils is largely misplaced, with only ''
Bowenia
The genus ''Bowenia'' includes two living and two fossil species of cycads in the family Stangeriaceae, sometimes placed in their own family Boweniaceae. They are entirely restricted to Australia. The two living species occur in Queensland. '' ...
'' dating to the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...
or earlier. Although the cycad lineage itself is ancient, most extant species have evolved in the last 12 million years.
Although the Mesozoic is sometimes called the "Age of Cycads," the foliage of cycads is very similar to other groups of extinct seed plants, such as
Bennettitales and
Nilssoniales, that are not closely related, and cycads were probably only a minor component of mid-Mesozoic floras.
The
family Stangeriaceae
Stangeriaceae is the smallest family of the cycads, including only two extant genera, ''Stangeria'' and '' Bowenia'', which both have an underground stem.
Taxonomy
Although the family was first published by Schimper and Schenk as Stangerieae, ...
(named for Dr.
William Stanger, 1811–1854), consisting of only three
extant species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
, is thought to be of Gondwanan origin, as fossils have been found in
Lower Cretaceous
Lower may refer to:
* Lower (surname)
* Lower Township, New Jersey
*Lower Receiver (firearms)
* Lower Wick Gloucestershire, England
See also
*Nizhny
Nizhny (russian: Ни́жний; masculine), Nizhnyaya (; feminine), or Nizhneye (russian: Н� ...
deposits in
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the List of South American countries by area, second-largest ...
, dating to . The family
Zamiaceae
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and subtropical regions of Africa, Australia and North and South Americ ...
is more diverse, with a fossil record extending from the middle
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...
to the
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
() in
North
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography.
Etymology
The word ''north ...
and South America,
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
, Australia, and
Antarctica, implying the family was present before the break-up of Pangea. The family
Cycadaceae
''Cycas'' is a genus of plants belonging to a very ancient lineage, the Cycadophyta, which are not closely related to palms, ferns, trees or any other modern group of plants. They are evergreen perennials which achieved their maximum diversity i ...
is thought to be an early offshoot from other cycads, with fossils from
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
deposits () in
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
, and
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
,
indicating this family originated in Laurasia. ''
Cycas'' is the only
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
in the family and contains 99 species, the most of any cycad genus.
Molecular data have recently shown ''Cycas'' species in
Australasia
Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologic ...
and the east coast of Africa are recent arrivals, suggesting
adaptive radiation
In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, alters biotic in ...
may have occurred. The current distribution of cycads may be due to radiations from a few ancestral types sequestered on Laurasia and Gondwana, or could be explained by
genetic drift
Genetic drift, also known as allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance.
Genetic drift may cause gene variants to disappear completely and there ...
following the separation of already evolved genera. Both explanations account for the strict
endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
across present continental lines.
Distribution
The living cycads are found across much of the
subtropical and
tropical parts of the world. The greatest diversity occurs in
South and
Central America
Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...
. They are also found in
Mexico
Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
, the
Antilles
The Antilles (; gcf, label=Antillean Creole, Antiy; es, Antillas; french: Antilles; nl, Antillen; ht, Antiy; pap, Antias; Jamaican Patois: ''Antiliiz'') is an archipelago bordered by the Caribbean Sea to the south and west, the Gulf of Mex ...
, southeastern
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
,
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
,
Melanesia
Melanesia (, ) is a subregion of Oceania in the southwestern Pacific Ocean. It extends from Indonesia's New Guinea in the west to Fiji in the east, and includes the Arafura Sea.
The region includes the four independent countries of Fiji, V ...
,
Micronesia
Micronesia (, ) is a subregion of Oceania, consisting of about 2,000 small islands in the western Pacific Ocean. It has a close shared cultural history with three other island regions: the Philippines to the west, Polynesia to the east, ...
,
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
,
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...
,
Bangladesh
Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mo ...
,
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
,
Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
,
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Afric ...
, and
southern
Southern may refer to:
Businesses
* China Southern Airlines, airline based in Guangzhou, China
* Southern Airways, defunct US airline
* Southern Air, air cargo transportation company based in Norwalk, Connecticut, US
* Southern Airways Express, M ...
and tropical
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, where at least 65
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
occur. Some can survive in harsh
desert or semi-desert
climate
Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...
s (
xerophytic), others in wet
rain forest conditions, and some in both. Some can grow in
sand
Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class ...
or even on
rock, some in oxygen-poor, swampy,
bog
A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...
-like soils rich in
organic material. Some are able to grow in full sun, some in full shade, and some in both. Some are
salt tolerant (
halophytes).
Species diversity of the extant cycads peaks at 17˚ 15"N and 28˚ 12"S, with a minor peak at the
equator. There is therefore not a
latitudinal diversity gradient
Species richness, or biodiversity, increases from the poles to the tropics for a wide variety of terrestrial and marine organisms, often referred to as the latitudinal diversity gradient. The latitudinal diversity gradient is one of the most wide ...
towards the equator but towards the
Tropic of Cancer and the
Tropic of Capricorn. However, the peak near the northern tropic is largely due to ''Cycas'' in Asia and ''Zamia'' in the New World, whereas the peak near the southern tropic is due to ''Cycas'' again, and also to the diverse genus ''Encephalartos'' in southern and central Africa, and ''Macrozamia'' in Australia. Thus, the distribution pattern of cycad species with latitude appears to be an artifact of the geographical isolation of the remaining cycad genera and their species, and perhaps because they are partly
xerophytic rather than simply
tropical.
Cultural significance
In
Vanuatu
Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of ...
, the cycad is known as ''namele'' and is an important symbol of traditional culture. It serves as a powerful
taboo sign,
and a pair of ''namele'' leaves appears on the
national flag and coat of arms. Together with the
nanggaria plant, another symbol of Vanuatu culture, the ''namele'' also gives its name to
Nagriamel, an indigenous political movement.
See also
*
Fossil Cycad National Monument, formerly in the U.S. state of South Dakota
Footnotes
References
External links
Palm Trees, Small Palms, Cycads, Bromeliads and tropical plantssite with thousands of large, high quality photos of cycads and associated flora. Includes information on habitat and cultivation.
*Hill KD (1998–2004) The Cycad Pages, Royal Botanic Gardens Sydney. http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/index.html
*
ttp://www.pacsoa.org.au/ Palm and Cycad Societies of Australia (PACSOA)The Cycad Society of South Africa ''
The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'' Magazine article on cycad collectorship and cycad smuggling
{{Taxonbar, from1=Q1089795, from2=Q157114, from3=Q5197912, from4=Q5605610
Dioecious plants
Cisuralian first appearances
Extant Permian first appearances