Gymnadenia conopsea known as the fragrant orchid or marsh fragrant orchid, is a herbaceous plant belonging to the family Orchidaceae native to northern Europe. The name of the genus Gymnadenia is formed from Greek words γυμνός and ἀδήν and refers to the characteristics of the organs for secreting nectar; the specific Latin name "conopsea" derives from the Greek κώνωψ meaning "mosquito-like" because of the similarity of the long spur of the flower with the mouthparts of a mosquito. The scientific binomial name of this plant was Orchis conopsea, proposed by the Swedish naturalist and botanist Carl von Linné in his Species Plantarum of 1753; the name has been subsequently amended to the one accepted, by the British botanist Robert Brown in 1813. In German, this plant is called Mücken Nacktdrüse. Gymnadenia conopsea reaches on average 20–60 centimetres of height, with a maximum of 80 centimetres; these plants are bulbous geophytes, as they bring their buds in underground tubers or bulbs, organs that annually produce new stems and flowers.
Furthermore, these orchids are "terrestrial", because unlike "epiphyte" species do not live at the expense of other plants of major sizes. The stem is robust, with a striated surface; the leaves are long and lanceolate and vary from 3 to 7. The leaf color is gray-green. Size of leaf: width 1 to 2 cm, length 10 – 25 cm; these orchids have two ovoidal bulbs webbed and with many small and short lobes. Size of tubers: 1 to 3.5 cm. The inflorescence is 5–25 centimetres long and it is composed of flowers gathered in dense cylindrical spikes; these inflorescences are scented and genes underlying eugenol production have been identified in Gymnadenia conopsea, Gymnadenia odoratissima and Gymnadenia densiflora. The flowers are petiolated, placed in the axils of long bracts and reach on average 8–14 centimetres, they have a distinctive three lobed lip and long spurs. Their light scent is similar to cloves, their colors vary from white and pink to pink-purple, more white. These flowers bloom from June to July.
They are pollinated by insects, including moths. The species is exclusively pollinated by moths; the most common pollinators are the small elephant hawk-moth, hummingbird hawk-moth, silver Y, burnished brass and large yellow underwing. Fruit set is high with an average of 73%; the seeds germination is conditioned by the presence of specific fungi. This plant is quite common throughout northern Europe with the exception of the Dinaric Alps. In Asia it is common in areas to the north of the Himalayas. Gymnadenia conopsea ssp. borealis has been recorded from Co. Donegal, Ireland in 2004; this species' habitat includes mountain meadows and pastures and fens. They grow on siliceous and calcareous substrate, mildly damp and with low nutritional value, at an altitude of 0–2,400 metres above sea level. Gymnadenia conopsea subsp. Conopsea Gymnadenia conopsea subsp. Montana Bisse Pignatti S. - Flora d'Italia - Edagricole – 1982, Vol. III Tutin, T. G. et al. - Flora Europaea, second edition - 1993 CLAESSENS, J. & J. KLEYNEN: The flower of the European Orchid – Form and function Data related to Gymnadenia conopsea at Wikispecies Biolib Gymnadenia conopsea Archive
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. The biological function of a flower is to effect reproduction by providing a mechanism for the union of sperm with eggs. Flowers may allow selfing; some flowers produce diaspores without fertilization. Flowers are the site where gametophytes develop. Many flowers have evolved to be attractive to animals, so as to cause them to be vectors for the transfer of pollen. After fertilization, the ovary of the flower develops into fruit containing seeds. In addition to facilitating the reproduction of flowering plants, flowers have long been admired and used by humans to bring beauty to their environment, as objects of romance, religion, medicine and as a source of food; the essential parts of a flower can be considered in two parts: the vegetative part, consisting of petals and associated structures in the perianth, the reproductive or sexual parts. A stereotypical flower consists of four kinds of structures attached to the tip of a short stalk.
Each of these kinds of parts is arranged in a whorl on the receptacle. The four main whorls are as follows: Collectively the calyx and corolla form the perianth. Calyx: the outermost whorl consisting of units called sepals. Corolla: the next whorl toward the apex, composed of units called petals, which are thin and colored to attract animals that help the process of pollination. Androecium: the next whorl, consisting of units called stamens. Stamens consist of two parts: a stalk called a filament, topped by an anther where pollen is produced by meiosis and dispersed. Gynoecium: the innermost whorl of a flower, consisting of one or more units called carpels; the carpel or multiple fused carpels form a hollow structure called an ovary, which produces ovules internally. Ovules are megasporangia and they in turn produce megaspores by meiosis which develop into female gametophytes; these give rise to egg cells. The gynoecium of a flower is described using an alternative terminology wherein the structure one sees in the innermost whorl is called a pistil.
A pistil may consist of a number of carpels fused together. The sticky tip of the pistil, the stigma, is the receptor of pollen; the supportive stalk, the style, becomes the pathway for pollen tubes to grow from pollen grains adhering to the stigma. The relationship to the gynoecium on the receptacle is described as hypogynous, perigynous, or epigynous. Although the arrangement described above is considered "typical", plant species show a wide variation in floral structure; these modifications have significance in the evolution of flowering plants and are used extensively by botanists to establish relationships among plant species. The four main parts of a flower are defined by their positions on the receptacle and not by their function. Many flowers lack some parts or parts may be modified into other functions and/or look like what is another part. In some families, like Ranunculaceae, the petals are reduced and in many species the sepals are colorful and petal-like. Other flowers have modified stamens.
Flowers show great variation and plant scientists describe this variation in a systematic way to identify and distinguish species. Specific terminology is used to describe their parts. Many flower parts are fused together; when petals are fused into a tube or ring that falls away as a single unit, they are sympetalous. Connate petals may have distinctive regions: the cylindrical base is the tube, the expanding region is the throat and the flaring outer region is the limb. A sympetalous flower, with bilateral symmetry with an upper and lower lip, is bilabiate. Flowers with connate petals or sepals may have various shaped corolla or calyx, including campanulate, tubular, salverform or rotate. Referring to "fusion," as it is done, appears questionable because at least some of the processes involved may be non-fusion processes. For example, the addition of intercalary growth at or below the base of the primordia of floral appendages such as sepals, petals and carpels may lead to a common base, not the result of fusion.
Many flowers have a symmetry. When the perianth is bisected through the central axis from any point and symmetrical halves are produced, the flower is said to be actinomorphic or regular, e.g. rose or trillium. This is an example of radial symmetry; when flowers are bisected and produce only one line that produces symmetrical halves, the flower is said to be irregular or zygomorphic, e.g. snapdragon or most orchids. Flowers may be directly attached to the plant at their base; the stem or stalk subtending a flower is called a peduncle. If a peduncle supports more than o
In botany, a stoma called a stomate, is a pore, found in the epidermis of leaves and other organs, that facilitates gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening; the term is used collectively to refer to the entire stomatal complex, consisting of the paired guard cells and the pore itself, referred to as the stomatal aperture. Air enters the plant through these openings by gaseous diffusion, contains carbon dioxide and oxygen, which are used in photosynthesis and respiration, respectively. Oxygen produced as a by-product of photosynthesis diffuses out to the atmosphere through these same openings. Water vapor diffuses through the stomata into the atmosphere in a process called transpiration. Stomata are present in the sporophyte generation of all land plant groups except liverworts. In vascular plants the number and distribution of stomata varies widely. Dicotyledons have more stomata on the lower surface of the leaves than the upper surface.
Monocotyledons such as onion and maize may have about the same number of stomata on both leaf surfaces. In plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely. Most tree species have stomata only on the lower leaf surface. Leaves with stomata on both the upper and lower leaf are called. Size varies across species, with end-to-end lengths ranging from 10 to 80 µm and width ranging from a few to 50 µm. Carbon dioxide, a key reactant in photosynthesis, is present in the atmosphere at a concentration of about 400 ppm. Most plants require the stomata to be open during daytime; the air spaces in the leaf are saturated with water vapour, which exits the leaf through the stomata. Therefore, plants cannot gain carbon dioxide without losing water vapour. Ordinarily, carbon dioxide is fixed to ribulose-1,5-bisphosphate by the enzyme RuBisCO in mesophyll cells exposed directly to the air spaces inside the leaf; this exacerbates the transpiration problem for two reasons: first, RuBisCo has a low affinity for carbon dioxide, second, it fixes oxygen to RuBP, wasting energy and carbon in a process called photorespiration.
For both of these reasons, RuBisCo needs high carbon dioxide concentrations, which means wide stomatal apertures and, as a consequence, high water loss. Narrower stomatal apertures can be used in conjunction with an intermediary molecule with a high carbon dioxide affinity, PEPcase. Retrieving the products of carbon fixation from PEPCase is an energy-intensive process, however; as a result, the PEPCase alternative is preferable only where water is limiting but light is plentiful, or where high temperatures increase the solubility of oxygen relative to that of carbon dioxide, magnifying RuBisCo's oxygenation problem. A group of desert plants called "CAM" plants open their stomata at night, use PEPcarboxylase to fix carbon dioxide and store the products in large vacuoles; the following day, they close their stomata and release the carbon dioxide fixed the previous night into the presence of RuBisCO. This saturates RuBisCO with carbon dioxide; this approach, however, is limited by the capacity to store fixed carbon in the vacuoles, so it is preferable only when water is limited.
However, most plants do not have the aforementioned facility and must therefore open and close their stomata during the daytime, in response to changing conditions, such as light intensity and carbon dioxide concentration. It is not certain how these responses work. However, the basic mechanism involves regulation of osmotic pressure; when conditions are conducive to stomatal opening, a proton pump drives protons from the guard cells. This means that the cells' electrical potential becomes negative; the negative potential opens potassium voltage-gated channels and so an uptake of potassium ions occurs. To maintain this internal negative voltage so that entry of potassium ions does not stop, negative ions balance the influx of potassium. In some cases, chloride ions enter, while in other plants the organic ion malate is produced in guard cells; this increase in solute concentration lowers the water potential inside the cell, which results in the diffusion of water into the cell through osmosis.
This increases the cell's turgor pressure. Because of rings of cellulose microfibrils that prevent the width of the guard cells from swelling, thus only allow the extra turgor pressure to elongate the guard cells, whose ends are held in place by surrounding epidermal cells, the two guard cells lengthen by bowing apart from one another, creating an open pore through which gas can move; when the roots begin to sense a water shortage in the soil, abscisic acid is released. ABA binds to receptor proteins in the guard cells' plasma membrane and cytosol, which first raises the pH of the cytosol of the cells and cause the concentration of free Ca2+ to increase in the cytosol due to influx from outside the cell and release of Ca2+ from internal stores such as the endoplasmic reticulum and vacuoles; this caus
Insects or Insecta are hexapod invertebrates and the largest group within the arthropod phylum. Definitions and circumscriptions vary; as used here, the term Insecta is synonymous with Ectognatha. Insects have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes and one pair of antennae. Insects are the most diverse group of animals; the total number of extant species is estimated at between ten million. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans. Nearly all insects hatch from eggs. Insect growth is constrained by the inelastic exoskeleton and development involves a series of molts; the immature stages differ from the adults in structure and habitat, can include a passive pupal stage in those groups that undergo four-stage metamorphosis. Insects that undergo three-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages.
The higher level relationship of the insects is unclear. Fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm; the most diverse insect groups appear to have coevolved with flowering plants. Adult insects move about by walking, flying, or sometimes swimming; as it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles, composed of the front & rear on one side with the middle on the other side. Insects are the only invertebrates to have evolved flight, all flying insects derive from one common ancestor. Many insects spend at least part of their lives under water, with larval adaptations that include gills, some adult insects are aquatic and have adaptations for swimming; some species, such as water striders, are capable of walking on the surface of water. Insects are solitary, but some, such as certain bees and termites, are social and live in large, well-organized colonies.
Some insects, such as earwigs, show maternal care, guarding their eggs and young. Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances. Other species communicate with sounds: crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyrid beetles communicate with light. Humans regard certain insects as pests, attempt to control them using insecticides, a host of other techniques; some insects damage crops by feeding on sap, fruits, or wood. Some species are parasitic, may vector diseases; some insects perform complex ecological roles. Insect pollinators are essential to the life cycle of many flowering plant species on which most organisms, including humans, are at least dependent. Many insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms produce silk and honey bees produce honey and both have been domesticated by humans.
Insects are consumed as food in 80% of the world's nations, by people in 3000 ethnic groups. Human activities have effects on insect biodiversity; the word "insect" comes from the Latin word insectum, meaning "with a notched or divided body", or "cut into", from the neuter singular perfect passive participle of insectare, "to cut into, to cut up", from in- "into" and secare "to cut". A calque of Greek ἔντομον, "cut into sections", Pliny the Elder introduced the Latin designation as a loan-translation of the Greek word ἔντομος or "insect", Aristotle's term for this class of life in reference to their "notched" bodies. "Insect" first appears documented in English in 1601 in Holland's translation of Pliny. Translations of Aristotle's term form the usual word for "insect" in Welsh, Serbo-Croatian, etc; the precise definition of the taxon Insecta and the equivalent English name "insect" varies. In the broadest circumscription, Insecta sensu lato consists of all hexapods. Traditionally, insects defined in this way were divided into "Apterygota" —the wingless insects—and Pterygota—the winged insects.
However, modern phylogenetic studies have shown that "Apterygota" is not monophyletic, so does not form a good taxon. A narrower circumscription restricts insects to those hexapods with external mouthparts, comprises only the last three groups in the table. In this sense, Insecta sensu stricto is equivalent to Ectognatha. In the narrowest circumscription, insects are restricted to hexapods that are either winged or descended from winged ancestors. Insecta sensu strictissimo is equivalent to Pterygota. For the purposes of this article, the middle definition is used; the evolutionary relationship of insects to other animal groups remains unclear. Although traditionally grouped with millipedes and centiped
Agriculture is the science and art of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to live in cities; the history of agriculture began thousands of years ago. After gathering wild grains beginning at least 105,000 years ago, nascent farmers began to plant them around 11,500 years ago. Pigs and cattle were domesticated over 10,000 years ago. Plants were independently cultivated in at least 11 regions of the world. Industrial agriculture based on large-scale monoculture in the twentieth century came to dominate agricultural output, though about 2 billion people still depended on subsistence agriculture into the twenty-first. Modern agronomy, plant breeding, agrochemicals such as pesticides and fertilizers, technological developments have increased yields, while causing widespread ecological and environmental damage. Selective breeding and modern practices in animal husbandry have increased the output of meat, but have raised concerns about animal welfare and environmental damage.
Environmental issues include contributions to global warming, depletion of aquifers, antibiotic resistance, growth hormones in industrial meat production. Genetically modified organisms are used, although some are banned in certain countries; the major agricultural products can be broadly grouped into foods, fibers and raw materials. Food classes include cereals, fruits, meat, milk and eggs. Over one-third of the world's workers are employed in agriculture, second only to the service sector, although the number of agricultural workers in developed countries has decreased over the centuries; the word agriculture is a late Middle English adaptation of Latin agricultūra, from ager, "field", which in its turn came from Greek αγρός, cultūra, "cultivation" or "growing". While agriculture refers to human activities, certain species of ant and ambrosia beetle cultivate crops. Agriculture is defined with varying scopes, in its broadest sense using natural resources to "produce commodities which maintain life, including food, forest products, horticultural crops, their related services".
Thus defined, it includes arable farming, animal husbandry and forestry, but horticulture and forestry are in practice excluded. The development of agriculture enabled the human population to grow many times larger than could be sustained by hunting and gathering. Agriculture began independently in different parts of the globe, included a diverse range of taxa, in at least 11 separate centres of origin. Wild grains were eaten from at least 105,000 years ago. From around 11,500 years ago, the eight Neolithic founder crops and einkorn wheat, hulled barley, lentils, bitter vetch, chick peas and flax were cultivated in the Levant. Rice was domesticated in China between 11,500 and 6,200 BC with the earliest known cultivation from 5,700 BC, followed by mung and azuki beans. Sheep were domesticated in Mesopotamia between 11,000 years ago. Cattle were domesticated from the wild aurochs in the areas of modern Turkey and Pakistan some 10,500 years ago. Pig production emerged in Eurasia, including Europe, East Asia and Southwest Asia, where wild boar were first domesticated about 10,500 years ago.
In the Andes of South America, the potato was domesticated between 10,000 and 7,000 years ago, along with beans, llamas and guinea pigs. Sugarcane and some root vegetables were domesticated in New Guinea around 9,000 years ago. Sorghum was domesticated in the Sahel region of Africa by 7,000 years ago. Cotton was domesticated in Peru by 5,600 years ago, was independently domesticated in Eurasia. In Mesoamerica, wild teosinte was bred into maize by 6,000 years ago. Scholars have offered multiple hypotheses to explain the historical origins of agriculture. Studies of the transition from hunter-gatherer to agricultural societies indicate an initial period of intensification and increasing sedentism. Wild stands, harvested started to be planted, came to be domesticated. In Eurasia, the Sumerians started to live in villages from about 8,000 BC, relying on the Tigris and Euphrates rivers and a canal system for irrigation. Ploughs appear in pictographs around 3,000 BC. Farmers grew wheat, vegetables such as lentils and onions, fruits including dates and figs.
Ancient Egyptian agriculture relied on its seasonal flooding. Farming started in the predynastic period at the end of the Paleolithic, after 10,000 BC. Staple food crops were grains such as wheat and barley, alongside industrial crops such as flax and papyrus. In India, wheat and jujube were domesticated by 9,000 BC, soon followed by sheep and goats. Cattle and goats were domesticated in Mehrgarh culture by 8,000–6,000 BC. Cotton was cultivated by the 5th-4th millennium BC. Archeological evidence indicates an animal-drawn plough from 2,500 BC in the Indus Valley Civilisation. In China, from the 5th century BC there was a nationwide granary system and widespread silk farming. Water-powered grain mills were in use followed by irrigation. By the late 2nd century, heavy ploughs had been developed with iron mouldboards; these spread westwards across Eurasia. Asian rice was domesticated 8,200–13,500 years ago – depending on the molecular clock estimate, used – on the Pearl River in southern China with a single genetic origin from the wild rice Oryza rufipogon
The East African lowland honey bee is a subspecies of the western honey bee. It is native to central and eastern Africa, though at the southern extreme it is replaced by the Cape honey bee; this subspecies has been determined to constitute one part of the ancestry of the Africanized bees spreading through America. The introduction of the Cape honey bee into northern South Africa poses a threat to East African lowland honey bees. If a female worker from a Cape honey bee colony enters an East African lowland honey bee nest, she is not attacked due to her resemblance to the East African lowland honey bee queen; as she is capable of parthenogenetic reproduction, she may begin laying eggs which hatch as "clones" of herself, which will lay eggs, causing the parasitic A. m. capensis workers to increase in number. The death of the host colony results from the dwindling numbers of A. m. scutellata workers that perform foraging duties, the death of the queen, before queen death, competition for egg laying between A. m. capensis workers and the queen.
When the colony dies, the capensis females will seek out a new host colony. A single East African lowland bee sting is no more venomous than a single European bee sting, though East African lowland honey bees respond more when disturbed than do European honey bees, they send out three to four times as many workers in response to a threat. They will pursue an intruder for a greater distance from the hive. Although people have died as a result of 100-300 stings, it has been estimated that the average lethal dose for an adult is 500-1,100 bee stings. In terms of industrial honey production, the African bee produces far less honey than its European counterpart, whilst producing more swarms and absconding. For this reason, African honey bees are less desirable than European honey bees, except where the proclivity of African bees give beekeepers no other option due to the Africans' tendency to invade and take over European nests; the appearance of the East African lowland honey bee is similar to the European bee.
However, the East African lowland honey bee is smaller. The average body length of a worker is 19 mm, its upper body is covered in fuzz, its abdomen is striped with black. The native habitat of Apis mellifera scutellata includes the eastern regions of Africa; the species was first imported across the Atlantic Ocean to Brazil before it spread to Central America, South America, southern areas of the United States. The Africanized honey bee thrives in tropical areas and is not well adapted for cold areas that receive heavy rainfall. Honey bees are challenged to balance energy consumption and replenishment in their pursuit of nectar. High thoracic temperatures required for foraging flight pose a thermoregulatory imbalance that honey bees attempt to alleviate by targeting particular viscosities and temperatures of nectar resources. In lower environmental temperatures where energy loss is more pronounced, it has been shown through Apis mellifera scutellata that honey bees seek warmer, less-concentrated and less-viscous nectar, an energetically favorable behavior.
Nectar, concentrated in sugar is more viscous and therefore reduces the speed of consumption and the size of honey bee crop loads. In cooler ambient temperatures, harvesting small, concentrated quantities of nectar does not allow honey bees to maintain the metabolism necessary for foraging flight. Harvesting warmer, less-viscous nectar is advantageous because of the energy gained by heat. Honey bees are able to make up for the energy lost by flying. In A. mellifera scutellata, it was found that crop loads were contained in the abdomen, though it remains unclear whether this balances out the aforementioned energy loss from the thorax during flight. It appears that the cost of harvesting less-viscous nectar is that it is less concentrated in sugar and would be an energetic loss for the honey bees. However, this is not the case; the relative advantage is so great that it is still more energetically favorable for a honey bee to collect warm nectar at low sugar concentrations Honey bees are energetically rewarded by harvesting nectar, warmer than ambient temperatures because they make up for energy loss during foraging and obtain more nectar more easily.
The bumblebee’s ability to differentiate flower warmth by color and target warmer flowers is one noted precedent for nectar temperature selection in honey bees. It has been noted that A. mellifera scutellata have higher rates of colony growth and swarming than European honey bees, a fitness advantage that allowed them to become an invasive species. A study by Fewell and Bertram was conducted to understand the source of these differences; the differences in fitness strategy were thought to be accounted for by the fact that African worker bees have a greater preference for pollen over nectar, a direct food resource for the emerging brood. Another important factor was thought to be differences between the species in age polyethism, or the allotment of different tasks as a honey bee ages. Young worker bees focus on in-hive assistance such as brood care, the younger African bee populations were thought to be one explanation for the emphasis on reproduction and colony expansion in the species; the study was interested in the role different colony social environments and different genetic variation might play in the fitness discrepancies b
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which includes moths. Adult butterflies have large brightly coloured wings, conspicuous, fluttering flight; the group comprises the large superfamily Papilionoidea, which contains at least one former group, the skippers, the most recent analyses suggest it contains the moth-butterflies. Butterfly fossils date to the Paleocene, about 56 million years ago. Butterflies have the typical four-stage insect life cycle. Winged adults lay eggs on the food plant; the caterpillars grow, sometimes rapidly, when developed, pupate in a chrysalis. When metamorphosis is complete, the pupal skin splits, the adult insect climbs out, after its wings have expanded and dried, it flies off; some butterflies in the tropics, have several generations in a year, while others have a single generation, a few in cold locations may take several years to pass through their entire life cycle. Butterflies are polymorphic, many species make use of camouflage and aposematism to evade their predators.
Some, like the monarch and the painted lady, migrate over long distances. Many butterflies are attacked by parasites or parasitoids, including wasps, protozoans and other invertebrates, or are preyed upon by other organisms; some species are pests because in their larval stages they can damage domestic trees. Larvae of a few butterflies eat harmful insects, a few are predators of ants, while others live as mutualists in association with ants. Culturally, butterflies are a popular motif in the literary arts; the Oxford English Dictionary derives the word straightforwardly from Old English butorflēoge, butter-fly. A possible source of the name is the bright yellow male of the brimstone; the earliest Lepidoptera fossils are of a small moth, Archaeolepis mane, of Jurassic age, around 190 million years ago. Butterflies evolved from moths, so while the butterflies are monophyletic, the moths are not; the oldest butterflies are from the Palaeocene MoClay or Fur Formation of Denmark 55 million years old.
The oldest American butterfly is the Late Eocene Prodryas persephone from the Florissant Fossil Beds 34 million years old. Traditionally, the butterflies have been divided into the superfamily Papilionoidea excluding the smaller groups of the Hesperiidae and the more moth-like Hedylidae of America. Phylogenetic analysis suggests that the traditional Papilionoidea is paraphyletic with respect to the other two groups, so they should both be included within Papilionoidea, to form a single butterfly group, thereby synonymous with the clade Rhopalocera. Butterfly adults are characterized by their four scale-covered wings, which give the Lepidoptera their name; these scales give butterfly wings their colour: they are pigmented with melanins that give them blacks and browns, as well as uric acid derivatives and flavones that give them yellows, but many of the blues, greens and iridescent colours are created by structural coloration produced by the micro-structures of the scales and hairs. As in all insects, the body is divided into three sections: the head and abdomen.
The thorax is composed of each with a pair of legs. In most families of butterfly the antennae are clubbed, unlike those of moths which may be threadlike or feathery; the long proboscis can be coiled. Nearly all butterflies are diurnal, have bright colours, hold their wings vertically above their bodies when at rest, unlike the majority of moths which fly by night, are cryptically coloured, either hold their wings flat or fold them over their bodies; some day-flying moths, such as the hummingbird hawk-moth, are exceptions to these rules. Butterfly larvae, have a hard head with strong mandibles used for cutting their food, most leaves, they have cylindrical bodies, with ten segments to the abdomen with short prolegs on segments 3–6 and 10. Many are well camouflaged; the pupa or chrysalis, unlike that of moths, is not wrapped in a cocoon. Many butterflies are sexually dimorphic. Most butterflies have the ZW sex-determination system where females are the heterogametic sex and males homogametic. Butterflies are distributed worldwide except Antarctica.
Of these, 775 are Nearctic. The monarch butterfly is native to the Americas, but in the nineteenth century or before, spread across the world, is now found in Australia, New Zealand, other parts of Oceania, the Iberian Peninsula, it is not clear.