Lepidoptera is an order of insects that includes butterflies and moths. About 180,000 species of the Lepidoptera are described, in 126 families and 46 superfamilies, 10 per cent of the total described species of living organisms, it is one of the most widespread and recognizable insect orders in the world. The Lepidoptera show many variations of the basic body structure that have evolved to gain advantages in lifestyle and distribution. Recent estimates suggest the order may have more species than earlier thought, is among the four most speciose orders, along with the Hymenoptera and Coleoptera. Lepidopteran species are characterized by more than three derived features; the most apparent is the presence of scales that cover the bodies, a proboscis. The scales are modified, flattened "hairs", give butterflies and moths their wide variety of colors and patterns. All species have some form of membranous wings, except for a few that have reduced wings or are wingless. Mating and the laying of eggs are carried out by adults near or on host plants for the larvae.
Like most other insects and moths are holometabolous, meaning they undergo complete metamorphosis. The larvae are called caterpillars, are different from their adult moth or butterfly forms, having a cylindrical body with a well-developed head, mandible mouth parts, three pairs of thoracic legs and from none up to five pairs of prolegs; as they grow, these larvae change in appearance, going through a series of stages called instars. Once matured, the larva develops into a pupa. A few butterflies and many moth species spin a silk case or cocoon prior to pupating, while others do not, instead going underground. A butterfly pupa, called a chrysalis, has a hard skin with no cocoon. Once the pupa has completed its metamorphosis, a sexually mature adult emerges; the Lepidoptera have, over millions of years, evolved a wide range of wing patterns and coloration ranging from drab moths akin to the related order Trichoptera, to the brightly colored and complex-patterned butterflies. Accordingly, this is the most recognized and popular of insect orders with many people involved in the observation, collection, rearing of, commerce in these insects.
A person who collects or studies this order is referred to as a lepidopterist. Butterflies and moths play an important role in the natural ecosystem as pollinators and as food in the food chain. In many species, the female may produce from 200 to 600 eggs, while in others, the number may approach 30,000 eggs in one day; the caterpillars hatching from these eggs can cause damage to large quantities of crops. Many moth and butterfly species are of economic interest by virtue of their role as pollinators, the silk they produce, or as pest species; the term was coined by Linnaeus in 1735 and is derived from Greek λεπίς, gen. λεπίδος and πτερόν. Sometimes, the term Rhopalocera is used for the clade of all butterfly species, derived from the Ancient Greek ῥόπαλον and κέρας meaning "club" and "horn" coming from the shape of the antennae of butterflies; the origins of the common names "butterfly" and "moth" are varied and obscure. The English word butterfly is with many variations in spelling. Other than that, the origin is unknown, although it could be derived from the pale yellow color of many species' wings suggesting the color of butter.
The species of Heterocera are called moths. The origins of the English word moth are more clear, deriving from the Old English moððe" from Common Germanic, its origins are related to Old English maða meaning "maggot" or from the root of "midge", which until the 16th century was used to indicate the larva in reference to devouring clothes. The etymological origins of the word "caterpillar", the larval form of butterflies and moths, are from the early 16th century, from Middle English catirpel, catirpeller an alteration of Old North French catepelose: cate, cat + pelose, hairy; the Lepidoptera are among the most successful groups of insects. They are found on all continents, except Antarctica, inhabit all terrestrial habitats ranging from desert to rainforest, from lowland grasslands to mountain plateaus, but always associated with higher plants angiosperms. Among the most northern dwelling species of butterflies and moths is the Arctic Apollo, found in the Arctic Circle in northeastern Yakutia, at an altitude of 1500 m above sea level.
In the Himalayas, various Apollo species such as Parnassius epaphus have been recorded to occur up to an altitude of 6,000 m above sea level. Some lepidopteran species exhibit symbiotic, phoretic, or parasitic lifestyles, inhabiting the bodies of organisms rather than the environment. Coprophagous pyralid moth species, called sloth moths, such as Bradipodicola hahneli and Cryptoses choloepi, are unusual in that they are found inhabiting the fur of sloths, mammals found in Central and South America. Two species of Tinea moths have been recorded as feeding on horny tissue and have been bred from the horns of cattle; the larva of Zenodochium coccivorella is an internal parasite of the coccid Kermes species. Many species have been recorded as breeding in natural materials or refuse such as owl pellets, bat caves, honeycombs or diseased fruit; as of 2007, there was 174,250 lepi
Argentina the Argentine Republic, is a country located in the southern half of South America. Sharing the bulk of the Southern Cone with Chile to the west, the country is bordered by Bolivia and Paraguay to the north, Brazil to the northeast and the South Atlantic Ocean to the east, the Drake Passage to the south. With a mainland area of 2,780,400 km2, Argentina is the eighth-largest country in the world, the fourth largest in the Americas, the largest Spanish-speaking nation; the sovereign state is subdivided into twenty-three provinces and one autonomous city, Buenos Aires, the federal capital of the nation as decided by Congress. The provinces and the capital exist under a federal system. Argentina claims sovereignty over part of Antarctica, the Falkland Islands, South Georgia and the South Sandwich Islands; the earliest recorded human presence in modern-day Argentina dates back to the Paleolithic period. The Inca Empire expanded to the northwest of the country in Pre-Columbian times; the country has its roots in Spanish colonization of the region during the 16th century.
Argentina rose as the successor state of the Viceroyalty of the Río de la Plata, a Spanish overseas viceroyalty founded in 1776. The declaration and fight for independence was followed by an extended civil war that lasted until 1861, culminating in the country's reorganization as a federation of provinces with Buenos Aires as its capital city; the country thereafter enjoyed relative peace and stability, with several waves of European immigration radically reshaping its cultural and demographic outlook. The almost-unparalleled increase in prosperity led to Argentina becoming the seventh wealthiest nation in the world by the early 20th century. Following the Great Depression in the 1930s, Argentina descended into political instability and economic decline that pushed it back into underdevelopment, though it remained among the fifteen richest countries for several decades. Following the death of President Juan Perón in 1974, his widow, Isabel Martínez de Perón, ascended to the presidency, she was overthrown in 1976 by a U.
S.-backed coup which installed a right-wing military dictatorship. The military government persecuted and murdered numerous political critics and leftists in the Dirty War, a period of state terrorism that lasted until the election of Raúl Alfonsín as President in 1983. Several of the junta's leaders were convicted of their crimes and sentenced to imprisonment. Argentina is a prominent regional power in the Southern Cone and Latin America, retains its historic status as a middle power in international affairs. Argentina has the second largest economy in South America, the third-largest in Latin America, membership in the G-15 and G-20 major economies, it is a founding member of the United Nations, World Bank, World Trade Organization, Union of South American Nations, Community of Latin American and Caribbean States and the Organization of Ibero-American States. Despite its history of economic instability, it ranks second highest in the Human Development Index in Latin America; the description of the country by the word Argentina has been found on a Venetian map in 1536.
In English the name "Argentina" comes from the Spanish language, however the naming itself is not Spanish, but Italian. Argentina means in Italian " of silver, silver coloured" borrowed from the Old French adjective argentine " of silver" > "silver coloured" mentioned in the 12th century. The French word argentine is the feminine form of argentin and derives from argent "silver" with the suffix -in; the Italian naming "Argentina" for the country implies Terra Argentina "land of silver" or Costa Argentina "coast of silver". In Italian, the adjective or the proper noun is used in an autonomous way as a substantive and replaces it and it is said l'Argentina; the name Argentina was first given by the Venetian and Genoese navigators, such as Giovanni Caboto. In Spanish and Portuguese, the words for "silver" are plata and prata and " of silver" is said plateado and prateado. Argentina was first associated with the silver mountains legend, widespread among the first European explorers of the La Plata Basin.
The first written use of the name in Spanish can be traced to La Argentina, a 1602 poem by Martín del Barco Centenera describing the region. Although "Argentina" was in common usage by the 18th century, the country was formally named "Viceroyalty of the Río de la Plata" by the Spanish Empire, "United Provinces of the Río de la Plata" after independence; the 1826 constitution included the first use of the name "Argentine Republic" in legal documents. The name "Argentine Confederation" was commonly used and was formalized in the Argentine Constitution of 1853. In 1860 a presidential decree settled the country's name as "Argentine Republic", that year's constitutional amendment ruled all the names since 1810 as valid. In the English language the country was traditionally called "the Argentine", mimicking the typical Spanish usage la Argentina and resulting from a mistaken shortening of the fuller name'Argentine Republic'.'The Argentine' fell out of fashion during the mid-to-late 20th century, now the country is referred to as "Argentina".
In the Spanish language "Argentina" is feminine, taking the feminine article "La" as the i
An arthropod is an invertebrate animal having an exoskeleton, a segmented body, paired jointed appendages. Arthropods form the phylum Euarthropoda, which includes insects, arachnids and crustaceans; the term Arthropoda as proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora. Arthropods are characterized by their jointed limbs and cuticle made of chitin mineralised with calcium carbonate; the arthropod body plan consists of each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Arthopods are bilaterally symmetrical and their body possesses an external skeleton; some species have wings. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments, they have over a million described species, making up more than 80 per cent of all described living animal species, some of which, unlike most other animals, are successful in dry environments. Arthropods range in size from the microscopic crustacean Stygotantulus up to the Japanese spider crab.
Arthropods' primary internal cavity is a haemocoel, which accommodates their internal organs, through which their haemolymph – analogue of blood – circulates. Like their exteriors, the internal organs of arthropods are built of repeated segments, their nervous system is "ladder-like", with paired ventral nerve cords running through all segments and forming paired ganglia in each segment. Their heads are formed by fusion of varying numbers of segments, their brains are formed by fusion of the ganglia of these segments and encircle the esophagus; the respiratory and excretory systems of arthropods vary, depending as much on their environment as on the subphylum to which they belong. Their vision relies on various combinations of compound eyes and pigment-pit ocelli: in most species the ocelli can only detect the direction from which light is coming, the compound eyes are the main source of information, but the main eyes of spiders are ocelli that can form images and, in a few cases, can swivel to track prey.
Arthropods have a wide range of chemical and mechanical sensors based on modifications of the many setae that project through their cuticles. Arthropods' methods of reproduction and development are diverse; the evolutionary ancestry of arthropods dates back to the Cambrian period. The group is regarded as monophyletic, many analyses support the placement of arthropods with cycloneuralians in a superphylum Ecdysozoa. Overall, the basal relationships of Metazoa are not yet well resolved; the relationships between various arthropod groups are still debated. Aquatic species use either external fertilization. All arthropods lay eggs, but scorpions give birth to live young after the eggs have hatched inside the mother. Arthropod hatchlings vary from miniature adults to grubs and caterpillars that lack jointed limbs and undergo a total metamorphosis to produce the adult form; the level of maternal care for hatchlings varies from nonexistent to the prolonged care provided by scorpions. Arthropods contribute to the human food supply both directly as food, more indirectly as pollinators of crops.
Some species are known to spread severe disease to humans and crops. The word arthropod comes from the Greek ἄρθρον árthron, "joint", πούς pous, i.e. "foot" or "leg", which together mean "jointed leg". Arthropods are invertebrates with jointed limbs; the exoskeleton or cuticles consists of a polymer of glucosamine. The cuticle of many crustaceans, beetle mites, millipedes is biomineralized with calcium carbonate. Calcification of the endosternite, an internal structure used for muscle attachments occur in some opiliones. Estimates of the number of arthropod species vary between 1,170,000 and 5 to 10 million and account for over 80 per cent of all known living animal species; the number of species remains difficult to determine. This is due to the census modeling assumptions projected onto other regions in order to scale up from counts at specific locations applied to the whole world. A study in 1992 estimated that there were 500,000 species of animals and plants in Costa Rica alone, of which 365,000 were arthropods.
They are important members of marine, freshwater and air ecosystems, are one of only two major animal groups that have adapted to life in dry environments. One arthropod sub-group, insects, is the most species-rich member of all ecological guilds in land and freshwater environments; the lightest insects weigh less than 25 micrograms. Some living crustaceans are much larger; the embryos of all arthropods are segmented, built from a series of repeated modules. The last common ancestor of living arthropods consisted of a series of undifferentiated segments, each with a pair of appendages that functioned as limbs. However, all known living and fossil arthropods have grouped segments into tagmata in which segments and their limbs are specialized in various ways; the three-
Saxifragaceae is a plant family with about 640 known species in 33 accepted genera. The flowers are actinomorphic, they have 5 or 10 stamens. Well known species include: Bergenia cordifolia Saxifraga stellaris Saxifraga oppositifolia Saxifraga paniculataParnassiaceae have sometimes been treated as part of this family, although they are only distantly genetically related and are now placed in Celastraceae; the family does not include the genus Sassafras, despite the related Latin etymology of the names. Saxifragaceae are found in the Northern Hemisphere, with centers of diversity in the Himalayas, East Asia, Western North America; the greatest diversity is in the Pacific Northwest region of North America. The family is divided into two main lineages – the saxifragoids, which includes genera Saxifraga and Saxifragella, the heucheroids, which includes all the other genera; the heucheroids are composed of eight tribes: Darmera, Peltoboykinia, Boykinia, Leptarrhena and Cascadia. Media related to Saxifragaceae at Wikimedia Commons "Saxifragaceae".
Encyclopædia Britannica. 24. 1911. Saxifragaceae in Topwalks
Biodiversity refers to the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic and ecosystem level. Terrestrial biodiversity is greater near the equator, the result of the warm climate and high primary productivity. Biodiversity is not distributed evenly on Earth, is richest in the tropics; these tropical forest ecosystems cover less than 10 percent of earth's surface, contain about 90 percent of the world's species. Marine biodiversity is highest along coasts in the Western Pacific, where sea surface temperature is highest, in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity. Biodiversity tends to cluster in hotspots, has been increasing through time, but will be to slow in the future. Rapid environmental changes cause mass extinctions. More than 99.9 percent of all species that lived on Earth, amounting to over five billion species, are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.
More in May 2016, scientists reported that 1 trillion species are estimated to be on Earth with only one-thousandth of one percent described. The total amount of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes. In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC. In July 2016, scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor of all organisms living on Earth; the age of the Earth is about 4.54 billion years. The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland. More in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia.
According to one of the researchers, "If life arose quickly on Earth.. it could be common in the universe."Since life began on Earth, five major mass extinctions and several minor events have led to large and sudden drops in biodiversity. The Phanerozoic eon marked a rapid growth in biodiversity via the Cambrian explosion—a period during which the majority of multicellular phyla first appeared; the next 400 million years included repeated, massive biodiversity losses classified as mass extinction events. In the Carboniferous, rainforest collapse led to a great loss of animal life; the Permian–Triassic extinction event, 251 million years ago, was the worst. The most recent, the Cretaceous–Paleogene extinction event, occurred 65 million years ago and has attracted more attention than others because it resulted in the extinction of the dinosaurs; the period since the emergence of humans has displayed an ongoing biodiversity reduction and an accompanying loss of genetic diversity. Named the Holocene extinction, the reduction is caused by human impacts habitat destruction.
Conversely, biodiversity positively impacts human health in a number of ways, although a few negative effects are studied. The United Nations designated 2011–2020 as the United Nations Decade on Biodiversity. 1916 - The term biological diversity was used first by J. Arthur Harris in "The Variable Desert," Scientific American, JSTOR 6182: "The bare statement that the region contains a flora rich in genera and species and of diverse geographic origin or affinity is inadequate as a description of its real biological diversity." 1975 - The term natural diversity was introduced 1980 - Thomas Lovejoy introduced the term biological diversity to the scientific community in a book.. It became used. 1985 -The contracted form biodiversity was coined by W. G. Rosen 1985 - The term "biodiversity" appears in the article, "A New Plan to Conserve the Earth's Biota" by Laura Tangley. 1988 - The term biodiversity first appeared in a publication. The present - the term has achieved widespread use. "Biodiversity" is most used to replace the more defined and long established terms, species diversity and species richness.
Biologists most define biodiversity as the "totality of genes and ecosystems of a region". An advantage of this definition is that it seems to describe most circumstances and presents a unified view of the traditional types of biological variety identified: taxonomic diversity ecological diversity morphological diversity functional diversity This multilevel construct is consistent with Datman and Lovejoy. An explicit definition consistent with this interpretation was first given in a paper by Bruce A. Wilcox commissioned by the International Union for the Conservation of Nature and Natural Resources for the 1982 World National Parks Conference. Wilcox's definition was "Biological diversity is the variety of life forms...at all levels of biologi
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians have a larval phase of their life cycle; the larva's appearance is very different from the adult form including different unique structures and organs that do not occur in the adult form. Their diet may be different. Larvae are adapted to environments separate from adults. For example, some larvae such as tadpoles live exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some species like barnacles, adults are immobile but their larvae are mobile, use their mobile larval form to distribute themselves; some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species, the larvae are fed by female workers.
In Ropalidia marginata the males are capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae. The larvae of some species do not develop further into the adult form; this is a type of neoteny. It is a misunderstanding; this could be the case, but the larval stage has evolved secondarily, as in insects. In these cases the larval form may differ more than the adult form from the group's common origin. Within Insects, only Endopterygotes show different types of larvae. Several classifications have been suggested by many entomologists, following classification is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types: Apodous larvae – no legs at all and are poorly sclerotized. Based on sclerotization, three apodous forms are recognized. Eucephalous – with well sclerotized head capsule. Found in Nematocera and Cerambycidae families. Hemicephalus – with a reduced head capsule, retractable in to the thorax.
Found in Tipulidae and Brachycera families. Acephalus – without head capsule. Found in Cyclorrhapha Protopod larvae – larva have many different forms and unlike a normal insect form, they hatch from eggs which contains little yolk. Ex. first instar larvae of parasitic hymenoptera. Polypod larvae – known as eruciform larvae, these larva have abdominal prolegs, in addition to usual thoracic legs, they poorly sclerotized and inactive. They live in close contact with the food. Best example is caterpillars of lepidopterans. Oligopod larvae – have well developed head capsule and mouthparts are similar to the adult, but without compound eyes, they have six legs. No abdominal prolegs. Two types can be seen: Campodeiform – well sclerotized, dorso-ventrally flattened body. Long legged predators with prognathous mouthparts.. Scarabeiform – poorly sclerotized, flat thorax and abdomen. Short legged and inactive burrowing forms.. Crustacean larvae Ichthyoplankton Spawn Non-larval animal juvenile stages and other life cycle stages: In Porifera: olynthus, gemmule In Cnidaria: ephyra, strobila, hydranth, medusa In Mollusca: paralarva, young cephalopods In Platyhelminthes: hydatid cyst In Bryozoa: avicularium In Acanthocephala: cystacanth In Insecta: Nymphs and naiads, immature forms in hemimetabolous insects Subimago, a juvenile that resembles the adult in Ephemeroptera Instar, intermediate between each ecdysis Pupa and chrysalis, intermediate stages between larva and imago Protozoan life cycle stages Apicomplexan life cycle Algal life cycle stages: Codiolum-phase Conchocelis-phase Marine larval ecology Media related to Larvae at Wikimedia Commons The dictionary definition of larva at Wiktionary Arenas-Mena, C.
Indirect development, transdifferentiation and the macroregulatory evolution of metazoans. Philosophical Transactions of the Royal Society B: Biological Sciences. Feb 27, 2010 Vol.365 no.1540 653-669 Brusca, R. C. & Brusca, G. J.. Invertebrates. Sunderland, Mass.: Sinauer Associates. Hall, B. K. & Wake, M. H. eds.. The Origin and Evolution of Larval Forms. San Diego: Academic Press. Leis, J. M. & Carson-Ewart, B. M. eds.. The Larvae of Indo-Pacific Coastal Fishes. An Identification Guide to Marine Fish Larvae. Fauna Malesiana handbooks, vol. 2. Brill, Leiden. Minelli, A.. The larva. In: Perspectives in Animal Phylogeny and Evolution. Oxford University Press. P. 160-170. Link. Shanks, A. L.. An Identification Guide to the Larval Marine Invertebrates of the Pacific Northwest. Oregon State University Press, Corvallis. 256 pp. Smith, D. & Johnson, K. B.. A Guide to Marine Coastal Plankton and Marine Invertebrate Larvae. Kendall/Hunt Plublishing Company. Stanwell-Smith, D. Hood, A. & Peck, L. S.. A field guide to the pelagic invertebrates larvae of the maritime Antarctic.
British Antarctic Survey, Cambridge. Thyssen, P. J.. Keys for Identification of Immature Insects. In: Amendt, J. et al.. Current Concepts in Forensic Entomology, chapter 2, pp. 25–42. Springer: Dordrecht
In botany, a fruit is the seed-bearing structure in flowering plants formed from the ovary after flowering. Fruits are the means. Edible fruits, in particular, have propagated with the movements of humans and animals in a symbiotic relationship as a means for seed dispersal and nutrition. Accordingly, fruits account for a substantial fraction of the world's agricultural output, some have acquired extensive cultural and symbolic meanings. In common language usage, "fruit" means the fleshy seed-associated structures of a plant that are sweet or sour, edible in the raw state, such as apples, grapes, lemons and strawberries. On the other hand, in botanical usage, "fruit" includes many structures that are not called "fruits", such as bean pods, corn kernels and wheat grains; the section of a fungus that produces spores is called a fruiting body. Many common terms for seeds and fruit do not correspond to the botanical classifications. In culinary terminology, a fruit is any sweet-tasting plant part a botanical fruit.
However, in botany, a fruit is the ripened ovary or carpel that contains seeds, a nut is a type of fruit and not a seed, a seed is a ripened ovule. Examples of culinary "vegetables" and nuts that are botanically fruit include corn, eggplant, sweet pepper, tomato. In addition, some spices, such as allspice and chili pepper, are fruits. In contrast, rhubarb is referred to as a fruit, because it is used to make sweet desserts such as pies, though only the petiole of the rhubarb plant is edible, edible gymnosperm seeds are given fruit names, e.g. ginkgo nuts and pine nuts. Botanically, a cereal grain, such as corn, rice, or wheat, is a kind of fruit, termed a caryopsis. However, the fruit wall is thin and is fused to the seed coat, so all of the edible grain is a seed; the outer edible layer, is the pericarp, formed from the ovary and surrounding the seeds, although in some species other tissues contribute to or form the edible portion. The pericarp may be described in three layers from outer to inner, the epicarp and endocarp.
Fruit that bears a prominent pointed terminal projection is said to be beaked. A fruit results from maturation of one or more flowers, the gynoecium of the flower forms all or part of the fruit. Inside the ovary/ovaries are one or more ovules where the megagametophyte contains the egg cell. After double fertilization, these ovules will become seeds; the ovules are fertilized in a process that starts with pollination, which involves the movement of pollen from the stamens to the stigma of flowers. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and two sperm are transferred from the pollen to the megagametophyte. Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process; the zygote will give rise to the embryo of the seed, the endosperm mother cell will give rise to endosperm, a nutritive tissue used by the embryo.
As the ovules develop into seeds, the ovary begins to ripen and the ovary wall, the pericarp, may become fleshy, or form a hard outer covering. In some multiseeded fruits, the extent to which the flesh develops is proportional to the number of fertilized ovules; the pericarp is differentiated into two or three distinct layers called the exocarp and endocarp. In some fruits simple fruits derived from an inferior ovary, other parts of the flower, fuse with the ovary and ripen with it. In other cases, the sepals, petals and/or stamens and style of the flower fall off; when such other floral parts are a significant part of the fruit, it is called an accessory fruit. Since other parts of the flower may contribute to the structure of the fruit, it is important to study flower structure to understand how a particular fruit forms. There are three general modes of fruit development: Apocarpous fruits develop from a single flower having one or more separate carpels, they are the simplest fruits. Syncarpous fruits develop from a single gynoecium having two or more carpels fused together.
Multiple fruits form from many different flowers. Plant scientists have grouped fruits into three main groups, simple fruits, aggregate fruits, composite or multiple fruits; the groupings are not evolutionarily relevant, since many diverse plant taxa may be in the same group, but reflect how the flower organs are arranged and how the fruits develop. Simple fruits can be either dry or fleshy, result from the ripening of a simple or compound ovary in a flower with only one pistil. Dry fruits may be either dehiscent, or indehiscent. Types of dry, simple fruits, examples of each, include: achene – most seen in aggregate fruits capsule – caryopsis – cypsela – an achene-like fruit derived from the individual florets in a capitulum. Fibrous drupe – follicle – is formed from a single carpel, opens by one suture