Amaranthaceae is a family of flowering plants known as the amaranth family, in reference to its type genus Amaranthus. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, making it the most species-rich lineage within its parent order, Caryophyllales. Most species subshrubs; some species are succulent. Many species have stems with thickened nodes; the wood of the perennial stem has a typical "anomalous" secondary growth. The leaves are simple and alternate, sometimes opposite, they never possess stipules. They are flat or terete, their shape is variable, with entire or toothed margins. In some species, the leaves are reduced to minute scales. In most cases, neither basal nor terminal aggregations of leaves occur; the flowers are solitary or aggregated in cymes, spikes, or panicles and perfect and actinomorphic. Some species have unisexual flowers. Bracts and bracteoles scarious. Flowers are regular with an herbaceous or scarious perianth of five tepals joined.
One to five stamens are opposite to tepals or alternating, inserting from a hypogynous disc, which may have appendages in some species. The anthers have four pollen sacs. In tribe Caroxyloneae, anthers have vesicular appendages; the pollen grains are spherical with many pores, with pore numbers from a few to 250. One to three carpels are fused to a superior ovary with one basal ovule. Idioblasts are found in the tissues; the diaspores are seeds or fruits, more the perianth persists and is modified in fruit for means of dispersal. Sometimes bracts and bracteoles may belong to the diaspore. More the fruit is a circumscissile capsule or a berry; the horizontal or vertical seed has a thickened or woody seed coat. The green or white embryo is either annular; the basic chromosome number is 8–9. Widespread in the Amaranthaceae is the occurrence of betalain pigments; the former Chenopodiaceae contain isoflavonoids. In phytochemical research, several methylenedioxyflavonols, triterpenoids and specific root-located carbohydrates have been found in these plants.
Although most of the family use the more common C3 photosynthesis pathway, around 800 species are C4 plants. Within the family, several types of C4 photosynthesis occur, about 17 different types of leaf anatomy are realized. Therefore, this photosynthesis pathway seems to have developed about 15 times independently during the evolution of the family. About two-thirds of the C4 species belong to the former Chenopodiaceae; the first occurrence of C4 photosynthesis dates from the early Miocene, about 24 million years ago, but in some groups, this pathway evolved much about 6 million years ago. The multiple origin of C4 photosynthesis in the Amaranthaceae is regarded as an evolutionary response to inexorably decreasing atmospheric CO2 levels, coupled with a more recent permanent shortage in water supply as well as high temperatures. Species with higher water-use efficiency had a selective advantage and were able to spread out into arid habitats. Amaranthaceae is a cosmopolitan family from the tropics to cool temperate regions.
The Amaranthaceae are predominantly tropical, whereas the former Chenopodiaceae have their centers of diversity in dry temperate and warm temperate areas. Many of the species are halophytes, grow in dry steppes or semi-deserts; some species, such as spinach or forms of beet, are used as vegetables. Forms of Beta vulgaris include sugar beet; the seeds of Amaranthus, lamb's quarters, quinoa and kañiwa are edible and are used as pseudocereals. Dysphania ambrosioides and Dysphania anthelmintica are used as medicinal herbs. Several amaranth species are used indirectly as a source of soda ash, such as members of the genus Salicornia. A number of species are popular garden ornamental plants species from the genera Alternanthera, Amaranthus and Iresine. Other species are considered weeds, e.g. redroot pigweed and alligatorweed, several are problematic invasive species in North America, including Kali tragus and Bassia scoparia. Many species are known to cause pollen allergies. In the APG IV system of 2016, as in the previous Angiosperm Phylogeny Group classifications, the family is placed in the order Caryophyllales and includes the plants treated as the family Chenopodiaceae.
The monophyly of this broadly defined Amaranthaceae has been supported by both morphological and phylogenetic analyses. The family Amaranthaceae was first published in 1789 by Antoine Laurent de Jussieu in Genera Plantarum, p. 87–88. The first publication of family Chenopodiaceae was in 1799 by Étienne Pierre Ventenat in Tableau du Regne Vegetal, 2, p. 253. The older name is now the valid scientific name of the extended Amaranthaceae; some publications still continued to use the family name Chenopodiaceae. Phylogenetic research revealed the important impact of the subfamil
Acanthaceae is a family of dicotyledonous flowering plants containing 250 genera and about 2500 species. Most are shrubs, or twining vines. Only a few species are distributed in temperate regions; the four main centres of distribution are Indonesia and Malaysia, Africa and Central America. Representatives of the family can be found in nearly every habitat, including dense or open forests, wet fields and valleys, sea coast and marine areas and mangrove forests. Plants in this family have simple, decussated leaves with entire margins, without stipules; the leaves may contain calcium carbonate concretions, seen as streaks on the surface. The flowers are perfect, zygomorphic to nearly actinomorphic, arranged in an inflorescence, either a spike, raceme, or cyme. A colorful bract subtends each flower; the calyx has four or five lobes. The fruit is a two-celled capsule, dehiscing somewhat explosively. In most species, the seeds are attached to a hooked stalk that ejects them from the capsule; this trait is shared by all members of the clade Acanthoideae.
A 1995 study of seed expulsion in Acanthaceae used high speed video pictures to show that retinacula propel seeds away from the parent plant when the fruits dehisce, thereby helping the plant gain maximum seed dispersal range. A species well known to temperate gardeners is bear's breeches, a herbaceous perennial plant with big leaves and flower spikes up to 2 m tall. Tropical genera familiar to gardeners include Justicia. Avicennia, a genus of mangrove trees placed in Verbenaceae or in its own family, Avicenniaceae, is included in Acanthaceae by the Angiosperm Phylogeny Group on the basis of molecular phylogenetic studies that show it to be associated with this family. Traditionally the most important part use in Acanthaceae is the leaves and they are used externally for wounds; some research has indicated that Acanthaceae possess antifungal, anti-inflammatory, anti-pyretic, insecticidal, immunomodulatory, anti-platelet aggregation and anti-viral potential. For instance, Acanthus ilicifolius, whose chemical composition has been researched, is used in ethnopharmaceutical applications, including in Indian and Chinese traditional medicine.
Various parts of Acanthus ilicifolius have been used to treat asthma, leprosy, snake bites, rheumatoid arthritis. The leaves of Acanthus ebracteatus, noted for their antioxidant properties, are used for making Thai herbal tea in Thailand and Indonesia. Phytochemical reports on family Acanthaceae are glycosides, benzonoids, phenolic compounds and triterpenoids. Since the first comprehensive classification of Acanthaceae in 1847 by Nees, there have been a few major revisions presented since for the whole family. Lindau, in 1895, divided the family into the subfamilies Mendoncioideae, Thunbergioideae and Acanthoideae. Critically, Mendoncioideae and Nelsonioideae do not possess retinaculate fruits—and it is this distinction, between classifying Acanthaceae into a family that includes those clades with non-retinaculate fruits and one that excludes them, that still persists to the modern day. Bremekamp, in 1965, presented a classification of Acanthaceae that differed from that of Lindau, for his Acanthaceae excluded genera that lack retinaculate fruits.
He placed Nelsonioideae within Scrophulariaceae, classified Thunbergiaceae and Mendonciaceae as distinct families and divided his Acanthaceae into two groups based on the presence or absence of cystoliths, articulate stems, monothecate anthers, colpate pollen. In Scotland and Vollesen's 2000 study, they accepted 221 genera and detailed five major groups within Acanthaceae s.s., equivalent to Acanthoideae Link sensu Lindau 1895. Out of those 221 genera, they placed 201 of them into seven infrafamilial taxa of Acanthaceae, leaving only 20 unplaced. In the current understanding of Acanthaceae, Acanthaceae s.s. includes only those clades with retinaculate fruits, while Acanthaceae s.l. includes those clades as well as Thunbergioideae and Avicennia. Much research, using both molecular data and fossils, has been conducted in recent years regarding the dating and distribution of the Acanthaceae and Lamiales lineage, although there still remains some ambiguity. In a 2004 study on the molecular phylogenetic dating of asterid flowering plants, researchers estimated 106 million years for the stem lineage of Lamiales, 67 MY for the stem lineage of Acanthaceae, 54 MY for the crown node of Acanthaceae.
These estimates are older than those based on fossils that can confidently be assigned to Lamiales, which are middle Eocene in age, ca. 48-37 MY. Palynomorphs that definitively show the existence of Acanthaceae are known from the upper Miocene, with the oldest ca. 22 MY. The 246 accepted genera, according to Germplasm Resources Information Network, are: Thomandersia Baill. → Thomandersiaceae Schwarzbach, Andrea E.. "Phylogenetic relationships of the mangrove family Avicenniaceae based on chloroplast and nuclear ribosomal DNA seq
Nectar is a sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. Common nectar-consuming pollinators include mosquitoes, wasps, bees and moths, hummingbirds and bats. Nectar plays an important role in the foraging economics and overall evolution of nectar-eating species. Nectar is the sugar source for honey, it is useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar. For example, the social wasp species Apoica flavissima relies on nectar as a primary food source. In turn, these wasps hunt agricultural pest insects as food for their young. For example, thread-waisted wasps are known for hunting caterpillars. Caterpillars however, do become butterflies and moths, which are important pollinators. Nectar secretion increases as the flower is visited by pollinators.
After pollination, the nectar is reabsorbed into the plant. Nectar is derived from the fabled drink of Greek gods; the word is derived as a compound of nek, meaning death, tar, meaning the ability to overcome. The common use of nectar refers to the "sweet liquid in flowers", first recorded in AD 1600. A nectary is floral tissue found in different locations in the flower; the different types of floral nectaries include sepal nectaries, petal nectaries, staminal nectaries found on the stamen, gynoecial nectaries found on the ovary tissue. The nectaries may vary in color and symmetry. Nectaries can be categorized as structural or non-structural. Structural nectaries refer to specific areas of tissue that exude nectar, such as the types of floral nectaries listed. Non-structural nectaries secrete nectar infrequently from non-differentiated tissues; the different types of floral nectaries coevolved depending on the pollinator that feeds on the plant's nectar. Nectar is secreted from epidermal cells of the nectaries by means of modified stomata.
The nectar comes from phloem with additional sugars that are secreted from the cells through vesicles packaged by the endoplasmic reticulum. Flowers that have longer nectaries sometimes have a vascular strand in the nectary to assist in transport over a longer distance.. Floral nectaries are used by plants to attract pollinators such as insects and other vertebrates; the pollinators feed on the nectar and depending on the location of the nectary the pollinator assists in fertilization and outcrossing of the plant as they brush against the reproductive organs, the stamen and pistil, of the plant and pick up or deposit pollen. Nectar from floral nectaries is sometimes used as a reward to insects, such as ants, that protect the plant from predators. Many floral families have evolved a nectar spur; these spurs are projections of various lengths formed from different tissues, such as the petals or sepals. They allow for pollinators to land on the elongated tissue and more reach the nectaries and obtain the nectar reward.
Different characteristics of the spur, such as its length or position in the flower, may determine the type of pollinator that visits the flower. Defense from herbivory is one of the roles of extrafloral nectaries. Floral nectaries can be involved in defense. In addition to the sugars found in nectar, certain proteins may be found in nectar secreted by floral nectaries. In tobacco plants, these proteins have antimicrobial and antifungal properties and can be secreted to defend the gynoecium from certain pathogens. Floral nectaries have evolved and diverged into the different types of nectaries due to the various pollinators that visit the flowers. In Melastomataceae, different types of floral nectaries have been lost many times. Flowers that ancestrally produced nectar and had nectaries may have lost their ability to produce nectar due to a lack of nectar consumption by pollinators, such as certain species of bees. Instead they focused on energy allocation to pollen production. Species of angiosperms that have nectaries use the nectar to attract pollinators that consume the nectar, such as birds and butterflies.
In Bromeliaceae, septal nectaries are common in species that are bird pollinated. In species that are wind pollinated, nectaries are absent because there is no pollinator to provide a reward for. In flowers that are pollinated by long-tongued organism such as certain flies, moths and birds, nectaries in the ovaries are common because they are able to reach the nectar reward when pollinating. Sepal and petal nectaries are more common in species that are pollinated by short-tongued insects that cannot reach so far into the flower. Extrafloral nectaries are nectar-secreting plant glands that develop outside of flowers and are not involved in pollination, they are diverse in form, location and mechanism. They have been described in all above-ground plant parts—including leaves, stipules, cotyledons and stems, among others, they range from single-celled trichomes to complex cup-like structures that may or may not be vascularized. In contrast to floral nectaries, nectar produced outside the flower have a defensive function.
The nectar attracts predatory insects whic
The epidermis is a single layer of cells that covers the leaves, flowers and stems of plants. It forms a boundary between the external environment; the epidermis serves several functions: it protects against water loss, regulates gas exchange, secretes metabolic compounds, absorbs water and mineral nutrients. The epidermis of most leaves shows dorsoventral anatomy: the upper and lower surfaces have somewhat different construction and may serve different functions. Woody stems and some other stem structures such as potato tubers produce a secondary covering called the periderm that replaces the epidermis as the protective covering; the epidermis is the outermost cell layer of the primary plant body. In some older works the cells of the leaf epidermis have been regarded as specialised parenchyma cells, but the established modern preference has long been to classify the epidermis as dermal tissue, whereas parenchyma is classified as ground tissue; the epidermis is the main component of the dermal tissue system of leaves, stems, flowers and seeds.
Most plants have an epidermis, a single cell layer thick. Some plants like Ficus elastica and Peperomia, which have periclinal cellular division within the protoderm of the leaves, have an epidermis with multiple cell layers. Epidermal cells are linked to each other and provide mechanical strength and protection to the plant; the walls of the epidermal cells of the above ground parts of plants contain cutin, are covered with a cuticle. The cuticle reduces water loss to the atmosphere, it is sometimes covered with wax in smooth sheets, plates, tubes or filaments; the wax layers give some plants a bluish surface color. Surface wax protects the plant from intense sunlight and wind; the underside of many leaves have a thinner cuticle than the top side, leaves of plants from dry climates have thickened cuticles to conserve water by reducing transpiration. The epidermal tissue includes several differentiated cell types: epidermal cells, guard cells, subsidiary cells, epidermal hairs; the epidermal cells are the most numerous and least specialized.
These are more elongated in the leaves of monocots than in those of dicots. Trichomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. In plants with secondary growth, the epidermis of roots and stems is replaced by a periderm through the action of a cork cambium; the leaf and stem epidermis is covered with pores called stomata, part of a stoma complex consisting of a pore surrounded on each side by chloroplast-containing guard cells, two to four subsidiary cells that lack chloroplasts. The stomata complex regulates the exchange of gases and water vapor between the outside air and the interior of the leaf; the stomata are more numerous over the abaxial epidermis of the leaf than the upper epidermis. An exception is floating leaves where all stomata are on the upper surface. Vertical leaves, such as those of many grasses have equal numbers of stomata on both surfaces.
The stoma is bounded by two guard cells. The guard cells differ from the epidermal cells in the following aspects: The guard cells are bean-shaped in surface view, while the epidermal cells are irregular in shape The guard cells contain chloroplasts, so they can manufacture food by photosynthesis Guard cells are the only epidermal cells that can make sugar. According to one theory, in sunlight the concentration of potassium ions increases in the guard cells. This, together with the sugars formed, lowers the water potential in the guard cells; as a result, water from other cells enter the guard cells by osmosis so they swell and become turgid. Because the guard cells have a thicker cellulose wall on one side of the cell, i.e. the side around the stomatal pore, the swollen guard cells become curved and pull the stomata open. At night, the sugar is used up and water leaves the guard cells, so they become flaccid and the stomatal pore closes. In this way, they reduce the amount of water vapour escaping from the leaf.
The plant epidermis consists of three main cell types: pavement cells, guard cells and their subsidiary cells that surround the stomata and trichomes, otherwise known as leaf hairs. The epidermis of petals form a variation of trichomes called conical cells. Trichomes develop at a distinct phase during leaf development, under the control of two major trichome specification genes: TTG and GL1; the process may be controlled by the plant hormones gibberellins, if not controlled, gibberellins have an effect on the development of the leaf hairs. GL1 causes endoreplication, the replication of DNA without subsequent cell division as well as cell expansion. GL1 turns on the expression of a second gene for trichome formation, GL2, which controls the final stages of trichome formation causing the cellular outgrowth. Arabidopsis thaliana uses the products of inhibitory genes to control the patterning of trichomes, such as TTG and TRY; the products of these genes will diffuse into the lateral cells, preventing them from forming trichomes and in the case of TRY promoting the formation of pavement cells.
Expression of the gene MIXTA, or its analogue in other species in the process of cel
Spiracles are openings on the surface of some animals, which lead to respiratory systems. The spiracle is a small hole behind each eye. In the primitive jawless fish the first gill opening behind the mouth is similar to the other gill opening. With the evolution of the jaw in the early jawed vertebrates, this gill slit was "caught" between the forward gill-rod and the next rod, the hyomandibular bone, supporting the jaw hinge and anchoring the jaw to the skull proper; the gill opening was closed off from below, the remaining opening was small and hole-like, is termed a "spiracle". The spiracle is still found in all cartilaginous fish except requiem sharks, hammerhead sharks, chimaeras, is found in some primitive bony fishes, it is seen as an otic notch in the skull of the extinct labyrinthodonts, is thought to be associated with the ear opening in amniotes and frogs. Insects and some more derived spiders have spiracles on their exoskeletons to allow air to enter the trachea. In the respiratory system of insects, the tracheal tubes deliver oxygen directly into the animals' tissues.
The spiracles can be closed in an efficient manner to reduce water loss. This is done by contracting closer muscles surrounding the spiracle. In order to open, the muscle relaxes; the closer muscle is controlled by the central nervous system but can react to localized chemical stimuli. Several aquatic insects have similar or alternative closing methods to prevent water from entering the trachea; the timing and duration of spiracle closures can affect the respiratory rates of the organism. Spiracles may be surrounded by hairs to minimize bulk air movement around the opening, thus minimize water loss. Chapman, R. F; the Insects. 1998. Cambridge University Press
Maharashtra is a state in the western peninsular region of India occupying a substantial portion of the Deccan plateau. It is third-largest state by area in India. Spread over 307,713 km2, it is bordered by the Arabian Sea to the west, the Indian states of Karnataka and Goa to the south and Chhattisgarh to the east and Dadra and Nagar Haveli to the north west, Madhya Pradesh to the north, it is the world's second-most populous subnational entity. It was formed by merging the western and south-western parts of the Bombay State and Vidarbha, the north-western parts of the Hyderabad State and splitting Saurashtra by the States Reorganisation Act, it has over 112 million inhabitants and its capital, has a population around 18 million making it the most populous urban area in India. Nagpur hosts the winter session of the state legislature. Pune is known as'Oxford of the East' due to the presence of several well-known educational institutions; the Godavari and the Krishna are the two major rivers in the state.
The Narmada and Tapi Rivers flow near Madhya Pradesh and Gujarat. Maharashtra is the third-most urbanized state of India. Prior to Indian independence, Maharashtra was chronologically ruled by the Satavahana dynasty, Rashtrakuta dynasty, Western Chalukyas, Deccan sultanates and Marathas, the British. Ruins, tombs and places of worship left by these rulers are dotted around the state, they include the UNESCO World Heritage Sites of the Ellora caves. The numerous forts are associated with the life of Chhatrapati Shivaji Maharaj. Maharashtra is the wealthiest state by all major economic parameters and the most industrialized state in India; the state continues to be the single largest contributor to the national economy with a share of 15% in the country's gross domestic product. Maharashtra accounts for 17% of the industrial output of the country and 16% of the country's service sector output; the economy of Maharashtra is the largest state economy in India with ₹27.96 lakh crore in GDP and a per capita GDP of ₹180,000.
The modern Marathi language developed from the Maharashtri Prakrit, the word Marhatta is found in the Jain Maharashtri literature. The terms Maharashtra, Maharashtri and Maratha may have derived from the same root. However, their exact etymology is uncertain; the most accepted theory among the linguistic scholars is that the words Maratha and Maharashtra derived from a combination of Maha and rashtrika, the name of a tribe or dynasty of petty chiefs ruling in the Deccan region. Another theory is that the term is derived from Maha and ratha / rathi, which refers to a skilful northern fighting force that migrated southward into the area. An alternative theory states that the term derives from Rashtra. However, this theory is somewhat controversial among modern scholars who believe it to be the Sanskritised interpretation of writers. Chalcolithic sites belonging to the Jorwe culture have been discovered throughout the state. Maharashtra was ruled by the Maurya Empire in the fourth and third centuries BCE.
Around 230 BCE, Maharashtra came under the rule of the Satavahana dynasty for 400 years. The greatest ruler of the Satavahana dynasty was Gautamiputra Satakarni. In 90 CE, son of the Satavahana king Satakarni, the "Lord of Dakshinapatha, wielder of the unchecked wheel of Sovereignty", made Junnar, 30 miles north of Pune, the capital of his kingdom; the state was ruled by Western Satraps, Gupta Empire, Gurjara-Pratihara, Kadambas, Chalukya Empire, Rashtrakuta Dynasty, Western Chalukya before the Yadava rule. The Buddhist Ajanta Caves in present-day Aurangabad display influences from the Satavahana and Vakataka style; the caves were excavated during this period. The Chalukya dynasty ruled from the sixth to the eighth centuries CE, the two prominent rulers were Pulakeshin II, who defeated the north Indian Emperor Harsha, Vikramaditya II, who defeated the Arab invaders in the eighth century; the Rashtrakuta dynasty ruled Maharashtra from the eighth to the tenth century. The Arab traveller Sulaiman described the ruler of the Rashtrakuta Dynasty as "one of the four great kings of the world".
Shilahara dynasty began as vassals of the Rashtrakuta dynasty which ruled the Deccan plateau between the eighth and tenth centuries. From the early 11th century to the 12th century, the Deccan Plateau, which includes a significant part of Maharashtra, was dominated by the Western Chalukya Empire and the Chola dynasty. Several battles were fought between the Western Chalukya empire and the Chola dynasty in the Deccan Plateau during the reigns of Raja Raja Chola I, Rajendra Chola I, Jayasimha II, Someshvara I, Vikramaditya VI. In the early 14th century, the Yadava Dynasty, which ruled most of present-day Maharashtra, was overthrown by the Delhi Sultanate ruler Ala-ud-din Khalji. Muhammad bin Tughluq conquered parts of the Deccan, temporarily shifted his capital from Delhi to Daulatabad in Maharashtra. After the collapse of the Tughluqs in 1347, the local Bahmani Sultanate of Gulbarga took over, governing the region for the next 150 years. After the break-up of the Bahamani sultanate in 1518, Maharashtra split into five Deccan Sultanates: Nizamshah of Ahmednagar, Adilshah of Bijapur, Qutubshah of Golkonda, Bidarshah of Bidar and Imadshah of Elichpur.
These kingdoms fought with each other. United, they decisively defeated the
Southeast Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China and Japan, east of India, west of Papua New Guinea, north of Australia. Southeast Asia is bordered to the north by East Asia, to the west by South Asia and the Bay of Bengal, to the east by Oceania and the Pacific Ocean, to the south by Australia and the Indian Ocean; the region is the only part of Asia that lies within the Southern Hemisphere, although the majority of it is in the Northern Hemisphere. In contemporary definition, Southeast Asia consists of two geographic regions: Mainland Southeast Asia known as Indochina, comprising parts of Northeast India, Laos, Thailand and West Malaysia. Maritime Southeast Asia known as Nusantara, the East Indies and Malay Archipelago, comprises the Andaman and Nicobar Islands of India, East Malaysia, the Philippines, East Timor, Christmas Island, the Cocos Islands. Taiwan is included in this grouping by many anthropologists; the region lies near the intersection of geological plates, with both heavy seismic and volcanic activities.
The Sunda Plate is the main plate of the region, featuring all Southeast Asian countries except Myanmar, northern Thailand, northern Laos, northern Vietnam, northern Luzon of the Philippines. The mountain ranges in Myanmar and peninsular Malaysia are part of the Alpide belt, while the islands of the Philippines are part of the Pacific Ring of Fire. Both seismic belts meet in Indonesia, causing the region to have high occurrences of earthquakes and volcanic eruptions. Southeast Asia covers about 4.5 million km2, 10.5% of Asia or 3% of earth's total land area. Its total population is about 8.5 % of the world's population. It is the third most populous geographical region in the world after East Asia; the region is culturally and ethnically diverse, with hundreds of languages spoken by different ethnic groups. Ten countries in the region are members of ASEAN, a regional organization established for economic, military and cultural integration amongst its members; the region, together with part of South Asia, was well known by Europeans as the East Indies or the Indies until the 20th century.
Chinese sources referred the region as 南洋, which means the "Southern Ocean." The mainland section of Southeast Asia was referred to as Indochina by European geographers due to its location between China and the Indian subcontinent and its having cultural influences from both neighboring regions. In the 20th century, the term became more restricted to territories of the former French Indochina; the maritime section of Southeast Asia is known as the Malay Archipelago, a term derived from the European concept of a Malay race. Another term for Maritime Southeast Asia is Insulindia, used to describe the region between Indochina and Australasia; the term "Southeast Asia" was first used in 1839 by American pastor Howard Malcolm in his book Travels in South-Eastern Asia. Malcolm only included the Mainland section and excluded the Maritime section in his definition of Southeast Asia; the term was used in the midst of World War II by the Allies, through the formation of South East Asia Command in 1943.
SEAC popularised the use of the term "Southeast Asia," although what constituted Southeast Asia was not fixed. However, by the late 1970s, a standard usage of the term "Southeast Asia" and the territories it encompasses had emerged. Although from a cultural or linguistic perspective the definitions of "Southeast Asia" may vary, the most common definitions nowadays include the area represented by the countries listed below. Ten of the eleven states of Southeast Asia are members of the Association of Southeast Asian Nations, while East Timor is an observer state. Papua New Guinea has stated that it might join ASEAN, is an observer. Sovereignty issues exist over some territories in the South China Sea; some southern parts of Mainland China, as well as Hong Kong and Taiwan, are considered as part of Southeast Asia by some authors. * Administrative centre in Putrajaya. Southeast Asia is geographically divided into two subregions, namely Mainland Southeast Asia and Maritime Southeast Asia. Mainland Southeast Asia includes: Maritime Southeast Asia includes: The Andaman and Nicobar Islands of India are geographically considered part of Maritime Southeast Asia.
Eastern Bangladesh and Northeast India have strong cultural ties with Southeast Asia and sometimes considered both South Asian and Southeast Asian. Sri Lanka has on some occasions been considered a part of Southeast Asia because of its cultural ties to mainland Southeast Asia; the rest of the island of New Guinea, not part of Indonesia, Papua New Guinea, is sometimes included, so are Palau and the Northern Mariana Islands, which were all part of the Spanish East Indies with strong cultural and linguistic ties to the region the Philippines. The eastern half of Indonesia and East Timor are considered to be biogeographically part of Oceania due to its distinctive faunal features. New Guinea and its surrounding islands are geologically considered as a part of Australian continent, connected via the Sahul Shelf; the region