Cycads are a group of seed plants The spermatophytes (also known as phanerogams) comprise those plants that produce seeds. They are a subset of the embryophytes or land plants. The living spermatophytes form five groups: characterized by a large crown of compound leaves In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. There is continued debate about whether the flatness of leaves evolved to expose the chloroplasts to more light or to increase the absorption of carbon dioxide. In either case, the adaption was made at the expense and a stout trunk In botany, trunk refers to the main reproductive member of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the trunk to the top, depending on the species. They are evergreen In botany, an evergreen plant is a plant having leaves all year round. This contrasts with deciduous plants, which completely lose their foliage for part of the year, gymnospermous Gymnosperm is a group of spermatophyte seed-bearing plants with ovules on scales, which are usually arranged in cone-like structures. The other major group of seed-bearing plants, the angiosperms, [from the Greek, 'angion' - container] have ovules enclosed in a carpel, a sporophyll with fused margins. A carpel consists of a stigma, style and the, dioecious Dioecious species are whose members can produce only one type of gamete; each individual organism belonging to a dioecious species is distinctly male or female . The majority of animal species (for example, all mammals and reptiles) are dioecious. In plant sexuality, there are also dioecious species plants having large pinnately compound leaves. They are frequently confused with and mistaken for palms Palm or Palmae or Panamea , the palm family, is a family of flowering plants, the only family in the monocot order Arecales. There are roughly 202 currently known genera with around 2600 species, most of which are restricted to tropical, subtropical, and warm temperate climates. Most palms are distinguished by their large, compound, evergreen or ferns A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. The group is also referred to as Polypodiophyta, or Polypodiopsida when treated as a subdivision of tracheophyta . The term "pteridophyte" has traditionally been used to describe all seedless, but are related to neither, belonging to the division In biology, a phylum [note 1] is a taxonomic rank below Kingdom and above Class. "Phylum" is equivalent to the botanical term division Cycadophyta.
Cycads are found across much of the subtropical and tropical parts of the world. They are found in South South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the and Central America Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. Most of Central America is considered to be part of the Mesoamerican biodiversity hotspot (where the greatest diversity occurs), Mexico The United Mexican States (Spanish: Estados Unidos Mexicanos ), commonly known as Mexico (English: /ˈmɛksɪkoʊ/) (Spanish: México (help·info) [ˈmexiko]), is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize,, the Antilles The Antilles refers to the islands forming the greater part of the West Indies in the Caribbean Sea. The Antilles are divided into two major groups: the "Greater Antilles" to the north including the larger islands of Cuba, Jamaica, Hispaniola (Haiti and the Dominican Republic), and Puerto Rico; and the smaller "Lesser Antilles", south-eastern United States of America The United States of America is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its 48 contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south, Australia Australia , officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the mainland, which is both the world's smallest continent and the world's largest island, the island of Tasmania, and numerous other islands in the Indian and Pacific Oceans.N4 Australia is the only place that is simultaneously considered a, Melanesia Melanesia literally means "islands of the black-skinned people". It is a subregion of Oceania extending from the western side of the West Pacific to the Arafura Sea, north and northeast of Australia. The term was first used by Jules Dumont d'Urville in 1832 to denote an ethnic and geographical grouping of islands distinct from Polynesia, Micronesia Micronesia [ˌmaɪkroʊˈniʒə] , from the Greek mikros (μικρός) (meaning small) and nesos (νῆσος) (meaning island), is a subregion of Oceania, comprising hundreds of small islands in the Pacific Ocean. The Philippines lie to the northwest, Indonesia, Papua New Guinea and Melanesia to the west and south, and Polynesia to the east, Japan Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters which make up Japan's name mean "sun-origin", which, China China has one of the world's oldest and continuous civilizations, consisting of states and cultures dating back more than six millennia.[citation needed] It has the world's longest continuously used written language system,[citation needed] and is viewed as the source of many major inventions. Historically, China's cultural sphere has extended, Southeast Asia Southeast Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India and north of Australia. The region lies on the intersection of geological plates, with heavy seismic and volcanic activity, India India, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal on the east, India has a coastline of 7,517, Sri Lanka Sri Lanka , officially the Democratic Socialist Republic of Sri Lanka (pronounced /ˌʃriːˈlæŋkə/, Sinhalese: ශ්රී ලංකාව, Tamil: இலங்கை; known as Ceylon (/sɪˈlɒn/) before 1972 and as Taprobane (/təˈprɒbəniː/) in ancient times), is an island country in South Asia, located about 31 kilometres (19.3 mi), Madagascar Madagascar, or Republic of Madagascar , is an island nation in the Indian Ocean off the southeastern coast of Africa. The main island, also called Madagascar, is the fourth-largest island in the world, and is home to 5% of the world's plant and animal species, of which more than 80% are endemic to Madagascar.[citation needed] They include the, and southern Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English and tropical Africa Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people (as of 2009, see table) in 61 territories, it accounts for about 14.8% of the World's human population, where at least 65 species occur. Some are renowned for survival in harsh semi-desert climates Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and numerous other meteorological elements in a given region over long periods of time. Climate can be contrasted to weather, which is the present condition of these same elements over periods up to two weeks, and can grow in sand Sand is a naturally occurring granular material composed of finely divided rock and mineral particles or even on rock In geology, rock is a naturally occurring solid aggregate of minerals and/or mineraloids. They are able to grow in full sun or shade, and some are salt Sodium chloride, also known as common salt, table salt, or halite, is an ionic compound with the formula Na tolerant. Though they are a minor component of the plant kingdom today, during the Jurassic The Jurassic is a geologic period and system that extends from about 199.6± 0.6 Ma to 145.5± 4 Ma, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the "Age of Reptiles". The start of the period is marked by the major Triassic– period they were extremely common.
They have very specialized pollinators A pollinator is the biotic agent that moves pollen from the male anthers of a flower to the female stigma of a flower to accomplish fertilization or syngamy of the female gamete in the ovule of the flower by the male gamete from the pollen grain. Though the terms are sometimes confused, a pollinator is different from a pollenizer, which is a plant and have been reported to fix nitrogen Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form in the atmosphere and converted into nitrogen compounds (such as ammonia, nitrate and nitrogen dioxide). This is an essential process for life because fixed nitrogen is needed to make nucleotides which are needed to make DNA and also to make amino in association with a cyanobacterium living in the roots. This blue-green algae Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" comes from the color of the bacteria (Greek: κυανός = blue). They are a significant component of the marine nitrogen cycle and an important primary produces a neurotoxin A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels called BMAA that is found in the seeds A seed ( /ˈsiːd/ ), referred to as a kernel in some plants, is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant. The formation of the seed completes of cycads.
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