There are about 380,000 known species of plants, of which the majority, some 260,000, produce seeds. They range in size from single cells to the tallest trees. Green plants provide a substantial proportion of the world's molecular oxygen; the sugars they create supply the energy for most of Earth's ecosystems and other organisms, including animals, either consume plants directly or rely on organisms which do so. (Full article...)
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Banksia aculeata, commonly known as prickly banksia, is a species of plant of the family Proteaceae native to the Stirling Range in the southwest of Western Australia. A shrub up to 2 m (7 ft) tall, it has dense foliage and leaves with very prickly serrated margins. Its unusual pinkish, pendent (hanging) flower spikes, known as inflorescences, are generally hidden in the foliage and appear during the early summer. Although it was collected by the naturalist James Drummond in the 1840s, Banksia aculeata was not formally described until 1981, by Alex George in his monograph of the genus.
A rare plant, Banksia aculeata is found in gravelly soils in elevated areas. Native to a habitat burnt by periodic bushfires, it is killed by fire and regenerates from seed afterwards. In contrast to other Western Australian banksias, it appears to have some resistance to the soil-borne water mouldPhytophthora cinnamomi. (Full article...)
Banksia violacea, commonly known as violet banksia, is a species of shrub or tree in the plant genus Banksia (family Proteaceae). It generally grows as a small shrub to 1.5 m (5 ft) high with fine narrow leaves, and is best known for its unusually coloured dark purple-violet inflorescences. The colour of the inflorescences, short leaves, and flattened follicles which are sticky when young, help identify this species from others in the field. It is found in low shrubland in southern regions of Western Australia from Esperance in the east to Narrogin in the west, growing exclusively in sandy soils.
First described in 1927 by the West Australian botanist Charles Gardner, the species was at one stage considered a variety of B. sphaerocarpa. Although there are no recognised subspecies or varieties, both lignotuberous and nonlignotuberous forms exist for Banksia violacea. Wasps, ants and flies have been recorded visiting flower spikes. Banksia violacea is classified as Not Threatened under the Wildlife Conservation Act of Western Australia. Regarded as of little value to floriculture, it is rarely cultivated. (Full article...)
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Banksia speciosa inflorescence
Banksia speciosa, commonly known as the showy banksia, is a species of large shrub or small tree in the familyProteaceae. It is found on the south coast of Western Australia between Hopetoun (33°57′ S) and the Great Australian Bight (approximately 33° S 130° E), growing on white or grey sand in shrubland. Reaching up to 8 m (26 ft) in height, it is a single-stemmed plant that has thin leaves with prominent triangular "teeth" along each margin, which are 20–45 cm (7.9–17.7 in) long and 2–4 cm (0.8–1.6 in) wide. The prominent cream-yellow flower spikes known as inflorescences appear throughout the year. As they age they develop up to 20 follicles each that store seeds until opened by fire. Though widely occurring, the species is highly sensitive to dieback and large populations of plants have succumbed to the disease.
Collected and described by Robert Brown in the early 19th century, B. speciosa is classified in the seriesBanksia within the genus. Its closest relative is B. baxteri. B. speciosa plants are killed by bushfire, and regenerate from seed. The flowers attract nectar- and insect-feeding birds, particularly honeyeaters, and a variety of insects. In cultivation, B. speciosa grows well in a sunny location on well-drained soil in areas with dry summers. It cannot be grown in areas with humid summers, though it has been grafted onto Banksia serrata or B. integrifolia. (Full article...)
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Grevillea juniperina, commonly known as juniper- or juniper-leaf grevillea or prickly spider-flower, is a plant of the family Proteaceae native to eastern New South Wales and southeastern Queensland in Australia. Scottish botanist Robert Brown described the species in 1810, and seven subspecies are recognised. One subspecies, G. j. juniperina, is restricted to Western Sydney and environs and is threatened by loss of habitat and housing development.
A small, prickly-leaved shrub between 0.2–3 m (0.66–9.84 ft) high, G. juniperina generally grows on clay-based or alluvial soils in eucalyptwoodland. The flower heads, known as inflorescences, appear from winter to early summer and are red, orange or yellow. Birds visit and pollinate the flowers. Grevillea juniperina plants are killed by bushfire, regenerating afterwards from seed. Grevillea juniperina adapts readily to cultivation and has been important in horticulture as it is the parent of many popular garden hybrids. (Full article...)
Banksia paludosa, commonly known as the marsh or swamp banksia, is a species of shrub in the plantgenusBanksia. It is native to New South Wales, Australia, where it is found between Sydney and Batemans Bay, with an isolated population further south around Eden. There are two recognised subspecies, the nominate of which is a spreading shrub to 1.5 m (4.9 ft) in height, and subsp. astrolux is a taller shrub to 5 m (16 ft) high found only in Nattai National Park.
Native mammals, such as the brown antechinus and sugar glider, are important pollinators of B. paludosa. Several species of honeyeaters visit the flower spikes, as do ants and the European honey bee. The response to bushfire depends on the subspecies; subspecies paludosa regenerates from underground lignotubers, while plants of subspecies astrolux are killed by fire and regenerate from large stores of seed which have been held in cones in the plant canopy. B. paludosa is sometimes seen in cultivation, with dwarf forms being registered and sold. (Full article...)
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Flowers emerging from base of cone
Isopogon anethifolius, commonly known as narrow-leaf drumsticks or narrow-leafed drumsticks, is a shrub in the family Proteaceae. The species is found only in coastal areas near Sydney in New South Wales, and to the immediate west. It occurs naturally in woodland, open forest and heathland on sandstone soils. An upright shrub, it can reach to 3 m (9.8 ft) in height, with terete leaves that are divided and narrow. The yellow flowers appear in the Spring, from September to December, and are prominently displayed. They are followed by round grey cones, which give the plant its common name of drumsticks. The small hairy seeds are found in the old flower parts.
Isopogon anethifolius regenerates after bushfire by resprouting from its woody base, known as a lignotuber, as well as from seed. It was described by Richard Salisbury in 1796, and was first grown in the United Kingdom the same year. One of the easiest members of the genus Isopogon to grow in cultivation, I. anethifolius grows readily in the garden if located in a sunny or part-shaded spot with sandy soil and good drainage. (Full article...)
Banksia oblongifolia, commonly known as the fern-leaved, dwarf or rusty banksia, is a species in the plant genusBanksia. Found along the eastern coast of Australia from Wollongong, New South Wales in the south to Rockhampton, Queensland in the north, it generally grows in sandy soils in heath, open forest or swamp margins and wet areas. A many-stemmed shrub up to 3 m (9.8 ft) high, it has leathery serrated leaves and rusty-coloured new growth. The yellow flower spikes, known as inflorescences, most commonly appear in autumn and early winter. Up to 80 follicles, or seed pods, develop on the spikes after flowering. Banksia oblongifolia resprouts from its woody lignotuber after bushfires, and the seed pods open and release seed when burnt, the seed germinating and growing on burnt ground. Some plants grow between fires from seed shed spontaneously.
Spanish botanist Antonio José CavanillesdescribedB. oblongifolia in 1800, though it was known as Banksia aspleniifolia in New South Wales for many years. However, the latter name, originally coined by Richard Anthony Salisbury, proved invalid, and Banksia oblongifolia has been universally adopted as the correct scientific name since 1981. Two varieties were recognised in 1987, but these have not been generally accepted. A wide array of mammals, birds, and invertebrates visit the inflorescences. Though easily grown as a garden plant, it is not commonly seen in horticulture. (Full article...)
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Symphyotrichum lateriflorum (formerly Aster lateriflorus) is a species of flowering plant in the aster family (Asteraceae). Commonly known as calico aster, starved aster, and white woodland aster, it is native to eastern and central North America. It is a perennial and herbaceous plant that may reach heights up to 120 centimeters (4 feet) and widths up to 30 centimeters (1 foot).
The flowers of calico aster are small compared to most Symphyotrichum species. They have an average of 7–15 short white ray florets, which are rarely tinted pink or purple. The flower centers, composed of disk florets, begin as cream to yellow and often become pink, purple, or brown as they mature. There are roughly 8–16 disk florets, each with five lobes that strongly reflex (bend backwards) when open. The mostly hairless leaves have a characteristic hairy midrib on their back faces, and branching is usually horizontal or in what can appear to be a zigzag pattern. Flower heads grow along one side of the branches and sometimes in clusters at the ends. (Full article...)
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Alloxylon pinnatum, known as Dorrigo waratah, is a tree of the family Proteaceae found in warm-temperate rainforest of south-east Queensland and northern New South Wales in eastern Australia. It has shiny green leaves that are either pinnate (lobed) and up to 30 cm (12 in) long, or lanceolate (spear-shaped) and up to 15 cm (5.9 in) long. The prominent pinkish-red flower heads, known as inflorescences, appear in spring and summer; these are made up of 50 to 140 individual flowers arranged in corymb or raceme. These are followed by rectangular woody seed pods, which bear two rows of winged seeds.
Known for many years as Oreocallis pinnata, it was transferred to the new genus Alloxylon by Peter Weston and Mike Crisp in 1991. This genus contains the four species previously classified in Oreocallis that are found in Australasia. Its terminal globular flowers indicate that the species is pollinated by birds. Classified as near threatened under the Queensland Nature Conservation Act 1992, the Dorrigo waratah has proven difficult to keep alive in cultivation. (Full article...)
Isopogon anemonifolius, commonly known as broad-leaved drumsticks, is a shrub of the family Proteaceae that is native only to eastern New South Wales in Australia. It occurs naturally in woodland, open forest, and heathland on sandstone soils. I. anemonifolius usually ranges between one and two metres in height, and is generally smaller in exposed heathland. Its leaves are divided and narrow, though broader than those of the related Isopogon anethifolius, and have a purplish tinge during the cooler months. The yellow flowers appear during late spring or early summer and are displayed prominently. They are followed by round grey cones, which give the plant its common name drumsticks. The small hairy seeds are found in the old flower parts.
A long-lived plant reaching an age of up to 60 years, I. anemonifolius resprouts from its woody base, known as a lignotuber, after bushfire. Seedlings appear in the year following a fire. Although I. anemonifolius was collected by Daniel Solander in 1770, it was not described until 1796 by Richard Salisbury. Several varieties have been named, though none are now recognised as distinct. It was first cultivated in the United Kingdom in 1791. I. anemonifolius grows readily in the garden if located in a sunny or part-shaded spot with sandy soil and good drainage. (Full article...)
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Acacia pycnantha, most commonly known as the golden wattle, is a tree of the family Fabaceae. It grows to a height of 8 metres (26 feet) and has phyllodes (flattened leaf stalks) instead of true leaves. The profuse fragrant, golden flowers appear in late winter and spring, followed by long seed pods. Explorer Thomas Mitchell collected the type specimen, from which George Bentham wrote the species description in 1842. The species is native to southeastern Australia as an understorey plant in eucalyptus forest. Plants are cross-pollinated by several species of honeyeater and thornbill, which visit nectaries on the phyllodes and brush against flowers, transferring pollen between them.
A. pycnantha has become a weed in areas of Australia, as well as in Africa and Eurasia. Its bark produces more tannin than any other wattle species, resulting in its commercial cultivation for production of this compound. It has been widely grown as an ornamental garden plant and for cut flower production. A. pycnantha was made the official floral emblem of Australia in 1988, and has been featured on the country's postal stamps. (Full article...)
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Several plants in cultivation
Drosera regia, commonly known as the king sundew, is a carnivorous plant in the sundew genus Drosera that is endemic to a single valley in South Africa. The genus name Drosera comes from the Greek word droseros, meaning "dew-covered". The specific epithetregia is derived from the Latin for "royal", a reference to the "striking appearance" of the species. Individual leaves can reach 70 cm (28 in) in length. It has many unusual relict characteristics not found in most other Drosera species, including woody rhizomes, operculatepollen, and the lack of circinate vernation in scape growth. All of these factors, combined with molecular data from phylogenetic analysis, contribute to the evidence that D. regia possesses some of the most ancient characteristics within the genus. Some of these are shared with the related Venus flytrap (Dionaea muscipula), which suggests a close evolutionary relationship.
The tentacle-covered leaves can capture large prey, such as beetles, moths, and butterflies. The tentacles of all Drosera species have special stalked glands on the leaf's upper surface that produce a sticky mucilage. The leaves are considered active flypaper traps that respond to captured prey by bending to surround it. In its native fynbos habitat, the plants compete for space with native marsh grasses and low evergreenshrubs. Of the two known populations of D. regia, the higher elevation site appears to be overgrown and is essentially extirpated. The lower elevation site is estimated to have about 50 mature plants, making it the most endangered Drosera species, since it is threatened with extinction in the wild. It is often cultivated by carnivorous plant enthusiasts, and a single cultivar has been registered. (Full article...)
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Approximate distribution of Hypericum sechmenii within Turkey
Hypericum sechmenii is a perennial herb that usually grows in clusters of stems 3–6 centimeters (1–2 inches) tall and blooms in June and July. The stems of the plant are smooth and lack hairs, while the leaves are leathery and do not have leafstalks. Its flowers are arranged in clusters that form a flat-topped shape known as a corymb, and each flower possesses five bright yellow petals. There are several species that are similar in appearance to H. sechmenii, with only minor physical differences that set them apart. The most closely related of these are Hypericum huber-morathii, Hypericum minutum, and Hypericum thymopsis. (Full article...)
In nature, B. sceptrum grows in deep yellow or pale red sand in tall shrubland, commonly on dunes, being found as a shrub to 5 metres (16 ft) high, though often smaller in exposed areas. It is killed by fire and regenerates by seed, the woody follicles opening with fire. B. sceptrum is one of the most striking yellow-flowered banksias of all. Its tall bright yellow spikes, known as inflorescences, are terminal and well displayed. Flowering is in summer, mainly December and January, though flowers are occasionally seen at other times. (Full article...)
The tree grows rapidly, and is capable of reaching heights of 15 metres (50 ft) in 25 years. While the species rarely lives more than 50 years, some specimens exceed 100 years of age. Its suckering ability allows this tree to clone itself indefinitely. It is considered a noxious weed and vigorous invasive species, and one of the worst invasive plant species in Europe and North America. In 21st-century North America, the invasiveness of the species has been compounded by its role in the life cycle of the also destructive and invasive spotted lanternfly. (Full article...)
Ethnobotany is the study of a region's plants and their practical uses through the traditional knowledge of a local culture and people. An ethnobotanist thus strives to document the local customs involving the practical uses of local flora for many aspects of life, such as plants as medicines, foods, intoxicants and clothing. Richard Evans Schultes, often referred to as the "father of ethnobotany", explained the discipline in this way:
Ethnobotany simply means investigating plants used by primitive societies in various parts of the world.
Since the time of Schultes, the field of ethnobotany has grown from simply acquiring ethnobotanical knowledge to that of applying it to a modern society, primarily in the form of pharmaceuticals. Intellectual property rights and benefit-sharing arrangements are important issues in ethnobotany. (Full article...)
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Utricularia vulgaris illustration from Jakob Sturm's "Deutschlands Flora in Abbildungen", Stuttgart (1796)
Utricularia, commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species (precise counts differ based on classification opinions; a 2001 publication lists 215 species). They occur in fresh water and wet soil as terrestrial or aquatic species across every continent except Antarctica. Utricularia are cultivated for their flowers, which are often compared with those of snapdragons and orchids, especially amongst carnivorous plant enthusiasts.
All Utricularia are carnivorous and capture small organisms by means of bladder-like traps. Terrestrial species tend to have tiny traps that feed on minute prey such as protozoa and rotifers swimming in water-saturated soil. The traps can range in size from 0.02 to 1.2 cm (0.008 to 0.5 in). Aquatic species, such as U. vulgaris (common bladderwort), possess bladders that are usually larger and can feed on more substantial prey such as water fleas (Daphnia), nematodes and even fish fry, mosquitolarvae and young tadpoles. Despite their small size, the traps are extremely sophisticated. In the active traps of the aquatic species, prey brush against trigger hairs connected to the trapdoor. The bladder, when "set", is under negative pressure in relation to its environment so that when the trapdoor is mechanically triggered, the prey, along with the water surrounding it, is sucked into the bladder. Once the bladder is full of water, the door closes again, the whole process taking only ten to fifteen milliseconds. (Full article...)
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Plants that produce toxins and/or cause irritation on contact are referred to as poisonous plants. The toxins in poisonous plants affect herbivores, and deter them from consuming the plants. Plants cannot move to escape their predators, so they must have other means of protecting themselves from herbivorous animals. Some plants have physical defenses such as thorns, spines and prickles, but by far the most common type of protection is chemical.
Over millennia, through the process of natural selection, plants have evolved the means to produce a vast and complicated array of chemical compounds to deter herbivores. Tannin, for example, is a defensive compound that emerged relatively early in the evolutionary history of plants, while more complex molecules such as polyacetylenes are found in younger groups of plants such as the Asterales. Many of the known plant defense compounds primarily defend against consumption by insects, though other animals, including humans, that consume such plants may also experience negative effects, ranging from mild discomfort to death. (Full article...)
Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it was understood that the pollination process involved both biotic and abiotic interactions. Charles Darwin's theories of natural selection utilized this work to build his theory of evolution, which includes analysis of the coevolution of flowers and their insectpollinators. (Full article...)
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Plant hormones (or phytohormones) are signal molecules, produced within plants, that occur in extremely low concentrations. Plant hormones control all aspects of plant growth and development, including embryogenesis, the regulation of organ size, pathogen defense, stress tolerance and reproductive development. Unlike in animals (in which hormone production is restricted to specialized glands) each plant cell is capable of producing hormones. Went and Thimann coined the term "phytohormone" and used it in the title of their 1937 book.
White tea, yellow tea, green tea, oolong, dark tea (which includes pu-erh tea) and black tea are all harvested from one of two major varieties grown today, C. sinensis var. sinensis and C. s. var. assamica, but are processed differently to attain varying levels of oxidation with black tea being the most oxidized and green being the least. Kukicha (twig tea) is also harvested from C. sinensis, but uses twigs and stems rather than leaves. (Full article...)
Historically, vascular plants were known as "higher plants", as it was believed that they were further evolved than other plants due to being more complex organisms. However, this is an antiquated remnant of the obsolete scala naturae, and the term is generally considered to be unscientific. (Full article...)
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An heirloom plant, heirloom variety, heritage fruit (Australia and New Zealand), or heirloom vegetable (especially in Ireland and the UK) is an old cultivar of a plant used for food that is grown and maintained by gardeners and farmers, particularly in isolated communities of the Western world. These were commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture.
In some parts of the world, it is illegal to sell seeds of cultivars that are not listed as approved for sale. The Henry Doubleday Research Association, now known as Garden Organic, responded to this legislation by setting up the Heritage Seed Library to preserve seeds of as many of the older cultivars as possible. However, seed banks alone have not been able to provide sufficient insurance against catastrophic loss. In some jurisdictions, like Colombia, laws have been proposed that would make seed saving itself illegal. (Full article...)
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Reconstruction of Rhynia gwynne-vaughanii
The rhyniophytes are a group of extinct early vascular plants that are considered to be similar to the genus Rhynia, found in the Early Devonian (around 419 to 393 million years ago). Sources vary in the name and rank used for this group, some treating it as the class Rhyniopsida, others as the subdivision Rhyniophytina or the division Rhyniophyta. The first definition of the group, under the name Rhyniophytina, was by Banks, since when there have been many redefinitions, including by Banks himself. "As a result, the Rhyniophytina have slowly dissolved into a heterogeneous collection of plants ... the group contains only one species on which all authors agree: the type species Rhynia gwynne-vaughanii". When defined very broadly, the group consists of plants with dichotomously branched, naked aerial axes ("stems") with terminal spore-bearing structures (sporangia). The rhyniophytes are considered to be stem group tracheophytes (vascular plants). (Full article...)
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A fine root is most commonly defined as a plant root that is two millimeters or less in diameter. Fine roots may function in acquisition of soil resources (eg. nutrients, water) and/or resource transport, making them functionally most analogous to the leaves and twigs in a plant's shoot system. Fine-root traits are variable between species and responsive to environmental conditions. Consequently, fine roots are studied to characterize the resource acquisition strategies and competitive ability of plant species. Categories of fine roots have been developed based on root diameter, position in a root system's branching hierarchy, and primary function. Fine roots are often associated with symbiotic fungi and play a role in many ecosystem processes like nutrient cycles and soil reinforcement. (Full article...)
Angiosperms are distinguished from the other seed-producing plants, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the common ancestor of all living gymnosperms before the end of the Carboniferous, over 300 million years ago. In the Cretaceous, angiosperms diversified explosively, becoming the dominant group of plants across the planet. (Full article...)
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Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN). Fossil plants are also covered by the code of nomenclature.
Ornamental bulbous plants, often called ornamental bulbs or just bulbs in gardening and horticulture, are herbaceousperennials grown for ornamental purposes, which have underground or near ground storage organs. Botanists distinguish between true bulbs, corms, rhizomes, tubers and tuberous roots, any of which may be termed "bulbs" in horticulture. Bulb species usually lose their upper parts during adverse conditions such as summer drought and heat or winter cold. The bulb's storage organs contain moisture and nutrients that are used to survive these adverse conditions in a dormant state. When conditions become favourable the reserves sustain a new growth cycle. In addition, bulbs permit vegetative or asexual multiplication in these species. Ornamental bulbs are used in parks and gardens and as cut flowers. (Full article...)
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Cylindropuntia imbricata, the cane cholla (walking stick cholla, tree cholla, or chainlink cactus), is a cactus found in the Southwestern United States and northern Mexico, including some cooler regions in comparison to many other cacti. It occurs primarily in the arid regions of the Southwestern United States in the states of Kansas, Oklahoma, Texas, New Mexico, Arizona, Colorado, and Nevada. It is often conspicuous because of its shrubby or even tree-like size, its silhouette, and its long-lasting yellowish fruits. (Full article...)
Roystonea regia, commonly known as the royal palm, Cuban royal palm, or Florida royal palm, is a species of palm native to Mexico, the Caribbean, Florida, and parts of Central America. A large and attractive palm, it has been planted throughout the tropics and subtropics as an ornamental tree. Although it is sometimes called R. elata, the conserved nameR. regia is now the correct name for the species. The royal palm reaches heights from 15–24 m (50–80 ft) tall. Populations in Cuba and Florida were long seen as separate species, but are now considered a single species.
Widely planted as an ornamental, R. regia is also used for thatch, construction timber, and in some forms of traditional medicine, although there is currently no valid scientific evidence to support the efficacy or use of any palm species for medicinal purposes. The fruit is eaten by birds and bats (which disperse the seeds) and fed to livestock. Its flowers are visited by birds and bats, and it serves as a roosting site and food source for a variety of animals. Roystonea regia is the national tree of Cuba, and has a religious role both in Santería and Christianity, where it is used in Palm Sunday observances. (Full article...)
Lilioid monocots (lilioids, liliid monocots, petaloid monocots, petaloid lilioid monocots) is an informal name used for a grade (grouping of taxa with common characteristics) of five monocotorders (Petrosaviales, Dioscoreales, Pandanales, Liliales and Asparagales) in which the majority of species have flowers with relatively large, coloured tepals. This characteristic is similar to that found in lilies ("lily-like"). Petaloid monocots refers to the flowers having tepals which all resemble petals (petaloid). The taxonomic terms Lilianae or Liliiflorae have also been applied to this assemblage at various times. From the early nineteenth century many of the species in this group of plants were put into a very broadly defined family, Liliaceaesensu lato or s.l. (lily family). These classification systems are still found in many books and other sources. Within the monocots the Liliaceae s.l. were distinguished from the Glumaceae.
The development of molecular phylogenetics, cladistic theory and phylogenetic methods in the 1990s resulted in a dismemberment of the Liliaceae and its subsequent redistribution across three lilioid orders (Liliales, Asparagales and Dioscoreales). Subsequent work has shown that two other more recently recognized orders, Petrosaviales and Pandanales also segregate with this group, resulting in the modern concept of five constituent orders within the lilioid monocot assemblage. This has resulted in treating monocots as three informal groups, alismatid, lilioid and commelinid monocots. The lilioids are paraphyletic in the sense that commelinids form a sister group to Asparagales. (Full article...)
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Portrait by Joseph Hornung, 1839
Augustin Pyramus (or Pyrame) de Candolle (UK: /kænˈdɒl/, US: /kɒ̃ˈdɔːl/, French:[kɑ̃dɔl]; 4 February 1778 – 9 September 1841) was a Swissbotanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at a herbarium. Within a couple of years de Candolle had established a new genus, and he went on to document hundreds of plant families and create a new natural plant classification system. Although de Candolle's main focus was botany, he also contributed to related fields such as phytogeography, agronomy, paleontology, medical botany, and economic botany.
De Candolle originated the idea of "Nature's war", which influenced Charles Darwin and the principle of natural selection. De Candolle recognized that multiple species may develop similar characteristics that did not appear in a common evolutionary ancestor; a phenomenon now known as convergent evolution. During his work with plants, de Candolle noticed that plant leaf movements follow a near-24-hour cycle in constant light, suggesting that an internal biological clock exists. Though many scientists doubted de Candolle's findings, experiments over a century later demonstrated that "the internal biological clock" indeed exists. (Full article...)
Systemin is a plant peptide hormone involved in the wound response in the family Solanaceae. It was the first plant hormone that was proven to be a peptide having been isolated from tomato leaves in 1991 by a group led by Clarence A. Ryan. Since then, other peptides with similar functions have been identified in tomato and outside of the Solanaceae. Hydroxyproline-rich glycopeptides were found in tobacco in 2001 and AtPeps (Arabidopsis thaliana Plant Elicitor Peptides) were found in Arabidopsis thaliana in 2006. Their precursors are found both in the cytoplasm and cell walls of plant cells, upon insect damage, the precursors are processed to produce one or more mature peptides. The receptor for systemin was first thought to be the same as the brassinolide receptor but this is now uncertain. The signal transduction processes that occur after the peptides bind are similar to the cytokine-mediated inflammatory immune response in animals. Early experiments showed that systemin travelled around the plant after insects had damaged the plant, activating systemic acquired resistance, now it is thought that it increases the production of jasmonic acid causing the same result. The main function of systemins is to coordinate defensive responses against insectherbivores but they also affect plant development. Systemin induces the production of protease inhibitors which protect against insect herbivores, other peptides activate defensins and modify root growth. They have also been shown to affect plants' responses to salt stress and UV radiation. AtPEPs have been shown to affect resistance against oomycetes and may allow A. thaliana to distinguish between different pathogens. In Nicotiana attenuata, some of the peptides have stopped being involved in defensive roles and instead affect flower morphology. (Full article...)
Wild species of cherry tree are widely distributed, mainly in the Northern Hemisphere. They are common in East Asia, especially in Japan, where they have been cultivated, producing many varieties. (Full article...)
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Asplenium montanum, commonly known as the mountain spleenwort, is a small fern endemic to the eastern United States. It is found primarily in the Appalachian Mountains from Vermont to Alabama, with a few isolated populations in the Ozarks and in the Ohio Valley. It grows in small crevices in sandstone cliffs with highly acid soil, where it is usually the only vascular plant occupying that ecological niche. It can be recognized by its tufts of dark blue-green, highly divided leaves. The species was first described in 1810 by the botanist Carl Ludwig Willdenow. No subspecies have been described, although a discolored and highly dissected form was reported from the Shawangunk Mountains in 1974. Asplenium montanum is a diploid member of the "Appalachian Asplenium complex," a group of spleenwort species and hybrids which have formed by reticulate evolution. Members of the complex descended from A. montanum are among the few other vascular plants that can tolerate its typical habitat. (Full article...)
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Postelsia palmaeformis growing in its native habitat at low tide
Postelsia palmaeformis, also known as the sea palm (not to be confused with the southern sea palm) or palm seaweed, is a species of kelp and classified within brown algae. It is the only known species in the genus Postelsia. The sea palm is found along the western coast of North America, on rocky shores with constant waves. It is one of the few algae that can survive and remain erect out of the water; in fact, it spends most of its life cycle exposed to the air. It is an annual, and edible, though harvesting of the alga is discouraged due to the species' sensitivity to overharvesting. (Full article...)
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Phragmipedium kovachii is an orchid species found to be new to science in 2001, native to the Andean cloud forests of northern Peru. A species with terrestrial habit and growing in clumps of several individuals, it displays showy pink to purple flowers up to 20 cm (8 in) wide. It is currently considered a critically endangered species by the IUCN, due to overcollection in the wild. (Full article...)
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Characteres generum plantarum (complete title Characteres generum plantarum, quas in Itinere ad Insulas Maris Australis, Collegerunt, Descripserunt, Delinearunt, annis MDCCLXXII-MDCCLXXV Joannes Reinoldus Forster et Georgius Forster, "Characteristics of the types of plants collected, described, and delineated during a voyage to islands of the South Seas, in the years 1772–1775 by Johann Reinhold Forster and Georg Forster") is a 1775/1776 book by Johann Reinhold Forster and Georg Forster about the botanical discoveries they made during the second voyage of James Cook.
The book contains 78 plates, the majority of which depict dissections of flowers at natural size. The book introduced 94 binomial names from 75 genera, of which 43 are still the accepted names today. Many plant genera were named after friends or patrons of the Forsters. The book was published in a folio and a quarto edition and translated into German in 1779. It is an important book as the earliest publication of names and descriptions of the native species of New Zealand. (Full article...)
An oak is a hardwood tree or shrub in the genusQuercus of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisphere; it includes some 500 species, both deciduous and evergreen. Fossil oaks date back to the Middle Eocene. Molecular phylogeny shows that the genus is divided into Old World and New World clades, but many oak species hybridise freely, making the genus's history difficult to resolve.
Ecologically, oaks are keystone species in habitats from Mediterranean semi-desert to subtropical rainforest. They live in association with many kinds of fungi including truffles. Oaks support more than 950 species of caterpillar, many kinds of gall wasp which form distinctive galls, roundish woody lumps such as the oak apple, and a large number of pests and diseases. Oak leaves and acorns contain enough tannin to be toxic to cattle, but pigs are able to digest them safely. Oak timber is strong and hard, and has found many uses in construction and furniture-making. The bark was traditionally used for tanning leather. Wine barrels are made of oak; these are used for aging alcoholic beverages such as sherry and whisky, giving them a range of flavours, colours, and aromas. The spongy bark of the cork oak is used to make traditional wine bottle corks. Almost a third of oak species are threatened with extinction due to climate change, invasive pests, and habitat loss. (Full article...)
Charlotte was born into the ruling family of Mecklenburg-Strelitz, a duchy in northern Germany. In 1760, the young and unmarried George III inherited the British throne. As Charlotte was a minor German princess with no interest in politics, George considered her a suitable consort, and they married in 1761. The marriage lasted 57 years and produced 15 children, 13 of whom survived to adulthood. They included two future British monarchs, George IV and William IV; as well as Charlotte, Princess Royal, who became Queen of Württemberg; and Prince Ernest Augustus, who became King of Hanover. (Full article...)
Rapaza viridis is the first known mixotroph (an organism that combines photosynthesis and ingestion of food) and kleptoplastic species within the phylumEuglenozoa. It eats microalgae by engulfing them—a process called phagocytosis—and then uses the chloroplasts from these algae to perform photosynthesis, altering the chloroplasts' structure in the process. In particular, Rapaza viridis can only feed on Tetraselmis cells native to their original environment, and will reject any other prey. (Full article...)
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In Slavic folklore, the raskovnik or razkovniche (SerbianCyrillic and Macedonian: расковник; Bulgarian: разковниче[rɐsˈkɔvnit͡ʃɛ]; Russian: разрыв-трава; Polish: rozryw) is a magical herb. According to lore, the raskovnik has the magical property to unlock or uncover anything that is locked or closed. However, legends claim it is notoriously difficult to recognize the herb, and reputedly only certain chthonic animals are able to identify it. (Full article...)
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A display of commercially-grown bulbs, including red and yellow cultivars.
An onion (Allium cepa L., from Latincepa meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus Allium. The shallot is a botanical variety of the onion which was classified as a separate species until 2011. Its close relatives include garlic, scallion, leek, and chive.
This genus also contains several other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion Allium fistulosum, the tree onionAllium × proliferum, and the Canada onion Allium canadense. The name wild onion is applied to a number of Allium species, but A. cepa is exclusively known from cultivation. Its ancestral wild original form is not known, although escapes from cultivation have become established in some regions. The onion is most frequently a biennial or a perennial plant, but is usually treated as an annual and harvested in its first growing season. (Full article...)
Image 2Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification; here, the specific name glauca means blue. (from Botany)
Image 3The Devonian marks the beginning of extensive land colonization by plants, which – through their effects on erosion and sedimentation – brought about significant climatic change. (from Evolutionary history of plants)
Image 5The trunk of early tree fern Psaronius, showing internal structure. The top of the plant would have been to the left of the image (from Evolutionary history of plants)
Image 10The fruit of Myristica fragrans, a species native to Indonesia, is the source of two valuable spices, the red aril (mace) enclosing the dark brown nutmeg. (from Botany)
Image 17Transverse section of a fossil stem of the Devonian vascular plant Rhynia gwynne-vaughani (from Botany)
Image 18Leaf lamina. The megaphyllous leaf architecture arose multiple times in different plant lineages (from Evolutionary history of plants)
Image 19A banded tube from the Late Silurian/Early Devonian. The bands are difficult to see on this specimen, as an opaque carbonaceous coating conceals much of the tube. Bands are just visible in places on the left half of the image. Scale bar: 20 μm (from Evolutionary history of plants)
Image 261 An oat coleoptile with the sun overhead. Auxin (pink) is evenly distributed in its tip. 2 With the sun at an angle and only shining on one side of the shoot, auxin moves to the opposite side and stimulates cell elongation there. 3 and 4 Extra growth on that side causes the shoot to bend towards the sun. (from Botany)
Image 29The Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale. (from Botany)
Image 30A nineteenth-century illustration showing the morphology of the roots, stems, leaves and flowers of the rice plant Oryza sativa (from Botany)
Image 31The evolution of syncarps. a: sporangia borne at tips of leaf b: Leaf curls up to protect sporangia c: leaf curls to form enclosed roll d: grouping of three rolls into a syncarp (from Evolutionary history of plants)
Image 35A late Siluriansporangium, artificially colored. Green: A spore tetrad. Blue: A spore bearing a trilete mark – the Y-shaped scar. The spores are about 30–35 μm across. (from Evolutionary history of plants)
Image 37Structure of Azadirachtin, a terpenoid produced by the Neem plant, which helps ward off microbes and insects. Many secondary metabolites have complex structures (from Evolutionary history of plants)