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...)
These are featured articles, which represent some of the best content on English Wikipedia.
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Second-year plant starting to flower, with a dead stem of the previous year, behind left
Verbascum thapsus, the great mullein, greater mullein or common mullein, is a species of mullein native to Europe, northern Africa, and Asia, and introduced in the Americas and Australia.
It is a hairy biennial plant that can grow to 2 m tall or more. Its small, yellow flowers are densely grouped on a tall stem, which grows from a large rosette of leaves. It grows in a wide variety of habitats, but prefers well-lit, disturbed soils, where it can appear soon after the ground receives light, from long-lived seeds that persist in the soil seed bank. It is a common weedy plant that spreads by prolifically producing seeds, and has become invasive in temperate world regions. It is a minor problem for most agricultural crops, since it is not a competitive species, being intolerant of shade from other plants and unable to survive tilling. It also hosts many insects, some of which can be harmful to other plants. Although individuals are easy to remove by hand, populations are difficult to eliminate permanently. (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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Dracophyllum fiordense, commonly known as the Fiordland grass tree, is a species of tree or shrub in the heath family, Ericaceae. It is endemic to the South Island of New Zealand. It reaches a height of 1.5–5.0 metres (5–16 feet) and has tufts of long green leaves at the ends of its branches. Each leaf has a distinctive curled spiral tip. D. fiordense has a pyramid-shaped inflorescence (flower spike) hidden under each clump of leaves, with between 113 and 120 pink flowers on each spike, and later reddish-brown dry fruit; both are around just 2 by 2 mm. It inhabits shrubland, lowland and subalpine forests, and tussock grassland of mountain slopes, gullies, and ridges. Its range covers two main areas: one in Fiordland National Park, and one in the Mount Cook and Westland National Parks.
D. fiordense was first described by the New Zealand naturalist Walter Oliver in 1928 and placed by him in the subgenus Dracophyllum. A cladistic analysis using genetic sequencing was published in 2010, which revealed that D. fiordense is closely related to D. menziesii as Oliver had hypothesised. Its conservation status was assessed in 2017 as "Declining". The kākāpō, a flightless bird, feeds on the bases of the leaves by making careful incisions in new shoots. D. fiordense is likely pollinated by insects and its seeds are later dispersed by the wind. (Full article...)
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'Blue Spire' cultivar
Salvia yangii, previously known as Perovskia atriplicifolia (/pəˈrɒvskiəætrɪplɪsɪˈfoʊliə/), and commonly called Russian sage, is a flowering herbaceousperennial plant and subshrub. Although not previously a member of Salvia, the genus widely known as sage, since 2017 it has been included within them. It has an upright habit, typically reaching 0.5–1.2 metres (1+1⁄2–4 feet) tall, with square stems and gray-green leaves that yield a distinctive odor when crushed. It is best known for its flowers. Its flowering season extends from mid-summer to late October, with blue to violet blossoms arranged into showy, branched panicles.
It is native to the steppes and hills of southwestern and central Asia. Successful over a wide range of climate and soil conditions, it has since become popular and widely planted. Several cultivars have been developed, differing primarily in leaf shape and overall height; 'Blue Spire' is the most common. This variation has been widely used in gardens and landscaping. S. yangii was the Perennial Plant Association's 1995 Plant of the Year, and the 'Blue Spire' cultivar received the Award of Garden Merit from the Royal Horticultural Society. (Full article...)
Ficus macrophylla, commonly known as the Moreton Bay fig or Australian banyan, is a large evergreen banyan tree of the Mulberry Family (Moraceae) native to eastern Australia, from the Wide Bay–Burnett region in the north to the Illawarra in New South Wales, as well as Lord Howe Island where the subspecies F. m. columnaris is a banyan form covering 2.5 acres (a hectare) or more of ground. Its common name is derived from Moreton Bay in Queensland, Australia. It is best known for its imposing buttress roots.
Ficus macrophylla is called a strangler fig because seed germination usually takes place in the canopy of a host tree, where the seedling lives as an epiphyte until its roots establish contact with the ground, when it enlarges and strangles its host, eventually becoming a freestanding tree by itself. Individuals may reach 60 m (200 ft) in height, with crown spreads as great as 250 feet (76 metres) being reported. Like all figs, it has an obligate mutualism with fig wasps; figs are pollinated only by fig wasps, and fig wasps can reproduce only in fig flowers. The wasp partner of the Moreton Bay Fig is Pleistodontes froggattii. Many species of birds, including pigeons, parrots, and various passerines, eat the fruit. (Full article...)
Banksia grossa is a species of shrub in the familyProteaceae and is endemic to Southwest Australia. It is one of fourteen species of banksia of the series Abietinae, all of which bear predominantly cylindrical or oval inflorescences. Collected in 1965, it was first formally described in 1981 by Alex George. Its thick leaves and large seeds distinguish it from other members of the Abietinae, and are the basis of its species name.
Found in sand or sand over laterite among heath between Eneabba and Badgingarra in Western Australia, the species grows as a many-stemmed shrub to 1 m (3.3 ft) high with narrow leaves and oval brownish flower spikes up to 10 cm (4 in) high, composed of hundreds of individual flowers. Flowering occurs throughout the cooler months of March to September. Flower spikes develop woody follicles which bear the seeds. After bushfire, Banksia grossa regenerates from its woody lignotuber; bushfires also stimulate the release of seeds, which germinate after disturbance. Visitors to (and likely pollinators of) inflorescences include insects and a nocturnal mammal, the white-tailed dunnart. (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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Brachychiton rupestris (commonly known as the narrow-leaved bottle tree or Queensland bottle tree) is a tree in the familyMalvaceae, endemic to Queensland, Australia. Described by Sir Thomas Mitchell and John Lindley in 1848, it earned its name from its bulbous trunk, which can be up to 3.5 metres (11 ft) in diameter at breast height (DBH). Reaching around 10–25 m (33–82 ft) high, the Queensland bottle tree is deciduous, losing its leaves seasonally, between September and December. The leaves are simple or divided, with one or more narrow leaf blades up to 11 centimetres (4 in) long and 2 cm (0.8 in) wide. Cream-coloured flowers appear from September to November, and are followed by woody, boat-shaped follicles that ripen from November to May. No subspecies are recognised.
As a drought deciduoussucculent tree, much like the baobab (Adansonia) of Madagascar, B. rupestris adapts readily to cultivation, and is quite tolerant of a range of soils and temperatures. It is a key component and emergent tree in the endangered central semi-evergreen vine thickets (also known as bottletree scrub) of the Queensland Brigalow Belt. Remnant trees are often left by farmers on cleared land for their value as shade and fodder trees, and as homes for various birds and animals. (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...)
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...)
The fruits are small, round, and yellow, and can ripen and turn red at any time of year, peaking in spring and summer. Like all figs, the fruit is in the form of a syconium, an inverted inflorescence with the flowers lining an internal cavity. F. rubiginosa is exclusively pollinated by the fig wasp species Pleistodontes imperialis, which may comprise four cryptospecies. The syconia are also home to another fourteen species of wasp, some of which induce galls while others parasitise the pollinator wasps and at least two species of nematode. Many species of bird, including pigeons, parrots, and various passerines, eat the fruit. Ranging along the Australian east coast from Queensland to Bega in southern New South Wales (including the Port Jackson area, leading to its alternative name), F. rubiginosa grows in rainforest margins and rocky outcrops. It is used as a shade tree in parks and public spaces, and when potted is well-suited for use as an indoor plant or in bonsai. (Full article...)
Aiphanes is a genus of spinypalms which is native to tropical regions of South and Central America and the Caribbean. There are about 26 species in the genus (see below), ranging in size from understorey shrubs with subterranean stems to subcanopy trees as tall as 20 metres (66 ft). Most have pinnately compound leaves (leaves which are divided into leaflets arranged feather-like, in pairs along a central axis); one species has entire leaves. Stems, leaves and sometimes even the fruit are covered with spines. Plants flower repeatedly over the course of their lifespan and have separate male and female flowers, although these are borne together on the same inflorescence. Although records of pollinators are limited, most species appear to be pollinated by insects. The fruit are eaten by several birds and mammals, including at least two species of amazon parrots.
Carl Ludwig Willdenow coined the name Aiphanes in 1801. Before that, species belonging to the genus had been placed in Bactris or Caryota. The name Martinezia had also been applied to the genus, and between 1847 and 1932 it was generally used in place of Aiphanes. Max Burret resurrected the name Aiphanes in 1932 and laid the basis for the modern concept of the genus. Aiphanes is most closely related to several other genera of spiny palms—Acrocomia, Astrocaryum, Bactris and Desmoncus. Two species are widely planted as ornamentals and the fruit, seeds or palm heart of several species have been eaten by indigenous peoples of the Americas for millennia. (Full article...)
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Banksia telmatiaea, commonly known as swamp fox banksia or rarely marsh banksia, is a shrub that grows in marshes and swamps along the lower west coast of Australia. It grows as an upright bush up to 2 metres (6 feet 7 inches) tall, with narrow leaves and a pale brown flower spike, which can produce profuse quantities of nectar. First collected in the 1840s, it was not published as a separate species until 1981; as with several other similar species it was previously included in B. sphaerocarpa (fox banksia).
The shrub grows amongst scrubland in seasonally wet lowland areas of the coastal sandplain between Badgingarra and Serpentine in Western Australia. A little studied species, not much is known of its ecology or conservation biology. Reports suggest that a variety of birds and small mammals pollinate it. Like many members of the series Abietinae, it has not been considered to have much horticultural potential and is rarely cultivated. (Full article...)
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Florida strangler fig in Deering Park, Florida
Ficus aurea, commonly known as the Florida strangler fig (or simply strangler fig), golden fig, or higuerón, is a tree in the family Moraceae that is native to the U.S. state of Florida, the northern and western Caribbean, southern Mexico and Central America south to Panama. The specific epithet aurea was applied by English botanist Thomas Nuttall who described the species in 1846.
Ficus aurea is a strangler fig. In figs of this group, seed germination usually takes place in the canopy of a host tree with the seedling living as an epiphyte until its roots establish contact with the ground. After that, it enlarges and strangles its host, eventually becoming a free-standing tree in its own right. Individuals may reach 30 m (100 ft) in height. Like all figs, it has an obligate mutualism with fig wasps: figs are only pollinated by fig wasps, and fig wasps can only reproduce in fig flowers. The tree provides habitat, food and shelter for a host of tropical lifeforms including epiphytes in cloud forests and birds, mammals, reptiles and invertebrates. F. aurea is used in traditional medicine, for live fencing, as an ornamental and as a bonsai. (Full article...)
Banksia menziesii, commonly known as firewood banksia, is a species of flowering plant in the family Proteaceae. It is a gnarled tree up to 10 m (33 ft) tall, or a lower spreading 1–3 m (3.3–9.8 ft) shrub in the more northern parts of its range. The serrated leaves are dull green with new growth a paler grey green. The prominent autumn and winter inflorescences are often two-coloured red or pink and yellow, and their colour has given rise to more unusual common names such as port wine banksia and strawberry banksia. Yellow blooms are rarely seen.
First described by the botanist Robert Brown in the early 19th century, no separate varieties of Banksia menziesii are recognised. It is found in Western Australia, from the Perth (32° S) region north to the Murchison River (27° S), and generally grows on sandy soils, in scrubland or low woodland. Banksia menziesii provides food for a wide array of invertebrate and vertebrate animals; birds and in particular honeyeaters are prominent visitors. A relatively hardy plant, Banksia menziesii is commonly seen in gardens, nature strips and parks in Australian urban areas with Mediterranean climates, but its sensitivity to dieback from the soil-borne water mould Phytophthora cinnamomi makes it short-lived in places with humid summers, such as Sydney. Banksia menziesii is widely used in the cut flower industry both in Australia and overseas. (Full article...)
Maize (Zea mays, Poaceae) is the most widely cultivated C4 plant.
In botany, C4 carbon fixation is one of three known methods of photosynthesis used by plants. C4 plants increase their photosynthetic efficiency by reducing or suppressing photorespiration, which mainly occurs under low atmospheric CO2 concentration, high light, high temperature, drought, and salinity. There are roughly 8,100 known C4 species, which belong to at least 61 distinct evolutionary lineages in 19 families (as per APG IV classification) of flowering plants. Among these are important crops such as maize, sorghum and sugarcane, but also weeds and invasive plants. Although only 3% of flowering plant species use C4 carbon fixation, they account for 23% of global primary production. The repeated, convergent C4 evolution from C3 ancestors has spurred hopes to bio-engineer the C4 pathway into C3 crops such as rice. C4 photosynthesis probably first evolved 30–35 million years ago in the Oligocene, and further origins occurred since, most of them in the last 15 million years. C4 plants are mainly found in tropical and warm-temperate regions, predominantly in open grasslands where they are often dominant. While most are graminoids, other growth forms such as forbs, vines, shrubs, and even some trees and aquatic plants are also known among C4 plants. (Full article...)
The arrival of humans around 50,000 years ago and the settlement by Europeans from 1788, has had a significant impact on the flora. The use of fire-stick farming by Aboriginal people led to significant changes in the distribution of plant species over time, and the large-scale modification or destruction of vegetation for agriculture and urban development since 1788 has altered the composition of most terrestrial ecosystems, leading to the extinction of 61 plant species by 2006, and endangering over 1000 more. (Full article...)
Iris is a flowering plantgenus of 310 accepted species with showy flowers. As well as being the scientific name, iris is also widely used as a common name for all Iris species, as well as some belonging to other closely related genera. A common name for some species is flags, while the plants of the subgenusScorpiris are widely known as junos, particularly in horticulture. It is a popular garden flower.
A field after application of a herbicide Herbicides (US: /ˈɜːrbɪsaɪdz/, UK: /ˈhɜːr-/), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds. Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called "total weed killers") kill plants indiscriminately. The combined effects of herbicides, nitrogen fertilizer, and improved cultivars has increased yields (per acre) of major crops by 3x to 6x from 1900 to 2000.
In the United States in 2012, about 91% of all herbicide usage, determined by weight applied, was in agriculture. In 2012, world pesticide expenditures totaled nearly $24.7 billion; herbicides were about 44% of those sales and constituted the biggest portion, followed by insecticides, fungicides, and fumigants. Herbicide is also used in forestry, where certain formulations have been found to suppress hardwood varieties in favor of conifers after clearcutting, as well as pasture systems. (Full article...)
Agroforestry can be practiced for economic, environmental, and social benefits, and can be part of sustainable agriculture. Apart from production, benefits from agroforestry include improved farm productivity, healthier environments, reduction of risk for farmers, beauty and aesthetics, increased farm profits, reduced soil erosion, creating wildlife habitat, less pollution, managing animal waste, increased biodiversity, improved soil structure, and carbon sequestration. (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 upper pitcher of Nepenthes lowii, a tropical pitcher plant that supplements its carnivorous diet with tree shrew droppings.
True carnivory is believed to have evolved independently at least 12 times in five different orders of flowering plants, and is represented by more than a dozen genera. This classification includes at least 583 species that attract, trap, and kill prey, absorbing the resulting available nutrients. Venus flytraps (Dionaea muscipula), pitcher plants, and bladderworts (Utricularia spp.) can be seen as exemplars of key traits genetically associated with carnivory: trap leaf development, prey digestion, and nutrient absorption. (Full article...)
Eucalyptus (/ˌjuːkəˈlɪptəs/) is a genus of more than 700 species of flowering plants in the family Myrtaceae. Most species of Eucalyptus are trees, often mallees, and a few are shrubs. Along with several other genera in the tribe Eucalypteae, including Corymbia and Angophora, they are commonly known as eucalypts or "gum trees". Plants in the genus Eucalyptus have bark that is either smooth, fibrous, hard, or stringy, the leaves have oil glands, and the sepals and petals are fused to form a "cap" or operculum over the stamens. The fruit is a woody capsule commonly referred to as a "gumnut".
Most species of Eucalyptus are native to Australia, and every state and territory has representative species. About three-quarters of Australian forests are eucalypt forests. Many eucalypt species have adapted to wildfire, are able to resprout after fire, or have seeds that survive fire. (Full article...)
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Some muscadines in a bowl; the green ones are scuppernongs. The scuppernong is a large variety of muscadine (Vitis rotundifolia), a species of grape native to the Southern United States. It is usually a greenish or bronze color and is similar in appearance and texture to a white grape, but rounder and larger and first known as the 'big white grape'. The grape is commonly known as the "scuplin" in some areas of the Deep South. It is also known as the "scufalum", "scupanon", "scupadine", "scuppernine", "scupnun", or "scufadine" in some parts of the South. The scuppernong is the state fruit of North Carolina. (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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Rice plant (Oryza sativa) with branched panicles containing many grains on each stem Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa (Asian rice)—or, much less commonly, O. glaberrima (African rice). Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2021, 787 million tons were produced, placing it fourth after sugarcane, maize, and wheat. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by diseases such as rice blast. Traditional rice polycultures such as rice-duck farming, and modern integrated pest management seek to control damage from pests in a sustainable way.
Many varieties of rice have been bred to improve crop quality and productivity. Biotechnology has created Green Revolution rice able to produce high yields when supplied with nitrogen fertiliser and managed intensively. Other products are rice able to express human proteins for medicinal use; flood-tolerant or deepwater rice; and drought-tolerant and salt-tolerant varieties. Rice is used as a model organism in biology. (Full article...)
Prunus is a genus of trees and shrubs in the flowering plant family Rosaceae that includes plums, cherries, peaches, nectarines, apricots, and almonds. The genus has a cosmopolitan distribution, being native to the North American temperate regions, the neotropics of South America, and temperate and tropical regions of Asia and Africa, There are 340 accepted species. Many members of the genus are widely cultivated for their fruit and for decorative purposes. Prunus fruit are drupes, or stone fruits. The fleshy mesocarp surrounding the endocarp is edible while the endocarp itself forms a hard, inedible shell called the pyrena ("stone" or "pit"). This shell encloses the seed (or "kernel"), which is edible in some species (such as sweet almonds), but poisonous in many others (such as apricots). Besides being eaten off the hand, most Prunus fruit are also commonly used in processing, such as jam production, canning, drying, and the seeds for roasting. (Full article...)
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Rafflesia keithii flower
The Rafflesiaceae are a family of rare parasiticplants comprising 36 species in 3 genera found in the tropical forests of east and southeast Asia, including Rafflesia arnoldii, which has the largest flowers of all plants. The plants are endoparasites of vines in the genus Tetrastigma (Vitaceae) and lack stems, leaves, roots, and any photosynthetic tissue. They rely entirely on their host plants for both water and nutrients, and only then emerge as flowers from the roots or lower stems of the host plants. (Full article...)
Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms "recessive" and "dominant" in reference to certain traits. In the preceding example, the green trait, which seems to have vanished in the first filial generation, is recessive and the yellow is dominant. He published his work in 1866, demonstrating the actions of invisible "factors"—now called genes—in predictably determining the traits of an organism. (Full article...)
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Australia, 1907: Cattlemen survey 700 cattle that were killed overnight by poisonous plants. 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...)
Cicuta, commonly known as water hemlock, is a genus of four species of highly poisonous plants in the family Apiaceae. They are perennialherbaceous plants which grow up to 2.5 meters (8 ft) tall, having distinctive small green or white flowers arranged in an umbrella shape (umbel). Plants in this genus may also be referred to as cowbane or poison parsnip. Cicuta is native to temperate regions of the Northern Hemisphere, mainly North America and Europe, typically growing in wet meadows, along streambanks and other wet and marshy areas. These plants bear a close resemblance to other members in the family Apiaceae and may be confused with a number of edible or poisonous plants. The common name hemlock may also be confused with poison hemlock (Conium maculatum), or with the Hemlock tree.
Water hemlock is considered one of North America's most toxic plants, being highly poisonous to humans. Three members of the genus contain a toxin named cicutoxin which causes central nervous system stimulatory effects including seizures following ingestion. Medical treatment of poisoning may include the use of activated charcoal to decrease gastrointestinal absorption of the toxic principle along with supportive care including anticonvulsant drugs such as a benzodiazepine. High doses of anticonvulsant medicine are often required to halt seizure activity and further medical care including intubation and mechanical ventilation may be required. (Full article...)
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Taputini, a pre-European cultivar of sweet potato (kūmara) from New Zealand
Sweet potato cultivation in Polynesia as a crop began around 1000 AD in central Polynesia. The plant became a common food across the region, especially in Hawaii, Easter Island and New Zealand, where it became a staple food. By the 17th century in central Polynesia, traditional cultivars were being replaced with hardier and larger varieties from the Americas (a process which began later in New Zealand, in the early 19th century). Many traditional cultivars are still grown across Polynesia, but they are rare and are not widely commercially grown.
It is unknown how sweet potato began to be cultivated in the Pacific, but the current scholarly consensus is that the presence of sweet potato in Polynesia is evidence of Polynesian contact with South America. However, some genetic studies of traditional cultivars suggest that sweet potato was first dispersed to Polynesia before human settlement. (Full article...)
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Portrait of Elfving, 1870s
Fredrik Emil Volmar Elfving (9 December 1854 – 21 June 1942) was a Swedish-speaking Finnish botanist, plant physiologist, and university administrator. During his university training, he frequently traveled abroad to learn new scientific methods and techniques from other prominent European scientists. Although his earliest publications dealt with phytogeography and phycology (particularly the green algae known as the desmids), his most notable research was in plant physiology. Early in his career, he published seminal work on the flow of water through the stems of woody plants, and investigated the phenomenon of transversely geotropic plant organs. In contrast to his works on plant physiology, his later experiments and views on lichens, which he himself considered his most important work, was far less favourably received.
Elfving became a Professor of botany at the University of Helsinki in 1892, a position he held until his retirement in 1926. A lively and enthusiastic teacher, Elfving revolutionized the teaching of botany at the university by introducing laboratory courses that emphasized the study of plant physiology, rather than taxonomy, as had been the tradition. During his time as professor, Elfving wrote many historical papers about scientific societies, and biographies of Scandinavian scientists. He wrote the books Tärkeimmät viljelyskasvit ("The Most Important Crops") and the Kasvitieteen oppikirja ("Botanical Textbook"), which were widely used as textbooks. Elfving has had several taxa named after him. (Full article...)
Acer rubrum, the red maple, also known as swamp maple, water maple, or soft maple, is one of the most common and widespread deciduous trees of eastern and central North America. The U.S. Forest Service recognizes it as the most abundant native tree in eastern North America. The red maple ranges from southeastern Manitoba around the Lake of the Woods on the border with Ontario and Minnesota, east to Newfoundland, south to Florida, and southwest to East Texas. Many of its features, especially its leaves, are quite variable in form. At maturity, it often attains a height around 30 m (100 ft). Its flowers, petioles, twigs, and seeds are all red to varying degrees. Among these features, however, it is best known for its brilliant deep scarlet foliage in autumn.
Over most of its range, red maple is adaptable to a very wide range of site conditions, perhaps more so than any other tree in eastern North America. It can be found growing in swamps, on poor, dry soils, and almost anywhere in between. It grows well from sea level to about 900 m (3,000 ft). Due to its attractive fall foliage and pleasing form, it is often used as a shade tree for landscapes. It is used commercially on a small scale for maple syrup production and for its medium to high quality lumber. It is also the state tree of Rhode Island. The red maple can be considered weedy or even invasive in young, highly disturbed forests, especially frequently logged forests. In a mature or old-growth northern hardwood forest, red maple only has a sparse presence, while shade-tolerant trees such as sugar maples, beeches, and hemlocks thrive. By removing red maple from a young forest recovering from disturbance, the natural cycle of forest regeneration is altered, changing the diversity of the forest for centuries to come. (Full article...)
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Osteospermum 'Pink Whirls' A cultivar selected for its intriguing and colourful flowers
A cultivar is a kind of cultivated plant that people have selected for desired traits and which retains those traits when propagated. Methods used to propagate cultivars include division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from deliberate human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars. Horticulturists generally believe the word cultivar was coined as a term meaning "cultivated variety".
Popular ornamental plants like roses, camellias, daffodils, rhododendrons, and azaleas are commonly cultivars produced by breeding and selection or as sports, for floral colour or size, plant form, or other desirable characteristics. Similarly, the world's agricultural food crops are almost exclusively cultivars that have been selected for characters such as improved yield, flavour, and resistance to disease, and very few wild plants are now used as food sources. Trees used in forestry are also special selections grown for their enhanced quality and yield of timber. (Full article...)
The leaflets of the plant are obovate-oblong and equal-sided, and of a silky texture. The fruits (legumes) are typically 1 to 2 in (25 to 51 mm) long and contain six or seven brownish seeds. The species typically grows in areas where the soils are relatively deep, especially in semi-arid and wadi areas, and on terraces and slight inclines and hills. (Full article...)
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Some traditional tools of botanical science The history of botany examines the human effort to understand life on Earth by tracing the historical development of the discipline of botany—that part of natural science dealing with organisms traditionally treated as plants.
Rudimentary botanical science began with empirically based plant lore passed from generation to generation in the oral traditions of paleolithichunter-gatherers. The first writings that show human curiosity about plants themselves, rather than the uses that could be made of them, appear in ancient Greece and ancient India. In Ancient Greece, the teachings of Aristotle's student Theophrastus at the Lyceum in ancient Athens in about 350 BC are considered the starting point for Western botany. In ancient India, the Vṛkṣāyurveda, attributed to Parashara, is also considered one of the earliest texts to describe various branches of botany. (Full article...)
Eucalyptus rhodantha, commonly known as rose mallee or rose gum, is a species of straggly mallee or shrub native to parts of Western Australia. It has smooth bark and a crown composed entirely of circular to heart-shaped juvenile leaves arranged in opposite pairs and attached directly to the stems with no stalks. The flower buds appear singly in the leaf axils and are red, the fruits hemispherical to conical and pendent. The rose mallee is grown as an ornamental shrub suitable for gardens in hot and dry climates. It is found more often in urban gardens and cultivation than in the wild and is readily available in seed form.
It is estimated that there are about 9000 species of liverworts. Some of the more familiar species grow as a flattened leafless thallus, but most species are leafy with a form very much like a flattened moss. Leafy species can be distinguished from the apparently similar mosses on the basis of a number of features, including their single-celled rhizoids. Leafy liverworts also differ from most (but not all) mosses in that their leaves never have a costa (present in many mosses) and may bear marginal cilia (very rare in mosses). Other differences are not universal for all mosses and liverworts, but the occurrence of leaves arranged in three ranks, the presence of deep lobes or segmented leaves, or a lack of clearly differentiated stem and leaves all point to the plant being a liverwort. Liverworts are distinguished from mosses in having unique complex oil bodies of high refractive index. (Full article...)
First described in 1821 by Jacques Choisy, the ambiguity of its original description meant that the species was often misidentified. Specimens were variously called H. elatum, H. anglicum, Androsaemum webbianum, and others. The species was placed into section Androsaemum of Hypericum by Norman Robson in 1984, and it is most closely related in appearance and classification to the other species in the section, especially H. androsaemum, H. hircinum, and H. × inodorum. The species is not used in modern medical applications, but may have anticancer potential and could be used to treat ear edemas. (Full article...)
Simarouba amara is a species of tree in the family Simaroubaceae, found in the rainforests and savannahs of South and Central America and the Caribbean. It was first described by Aubl. in French Guiana in 1775 and is one of six species of Simarouba. The tree is evergreen, but produces a new set of leaves once a year. It requires relatively high levels of light to grow and grows rapidly in these conditions, but lives for a relatively short time. In Panama, it flowers during the dry season in February and March, whereas in Costa Rica, where there is no dry season it flowers later, between March and July. As the species is dioecious, the trees are either male or female and only produce male or female flowers. The small yellow flowers are thought to be pollinated by insects, the resulting fruits are dispersed by animals including monkeys, birds and fruit-eating bats and the seeds are also dispersed by leaf cutter ants.
Simarouba amara has been studied extensively by scientists in an attempt to understand the tree and also to gain a better understanding of the ecology of the rainforest in general. Many of these studies were conducted on Barro Colorado Island in Panama or at La Selva Biological Station in Costa Rica. Of particular interest is how it competes with other species and with individuals of the same species at different stages in its life cycle. The seedlings are normally limited by the amount of light and nutrients found where they are growing and the saplings are considered relatively light demanding compared to other species. Young individuals are more likely to survive when they grow further away from their parents and when there are few other individuals growing near to them, which may be due to them being able to escape diseases. Plant physiologists have investigated how the leaves of the tree differ depending on their location in the forest canopy finding they are thicker in the canopy and thinner in the understory. They have also measured how the water potential of their leaves changes and when their stomata open and close during the day; the findings suggest that rather than closing their stomata to control water loss, it is controlled by the leaf area instead. Population geneticists have examined the way in which its genes vary, at both the local scale and across its range using microsatellites. It is genetically diverse, indicating gene flow occurs between populations and seeds can be dispersed up to 1 km. The leaves of S. amara are eaten by several species of caterpillar, particularly those in the genus Atteva. Several species of termite and ants live on or around the tree and lianas and epiphytes grow on the tree. (Full article...)
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Diversity of stramenopiles
The Stramenopiles, also called Heterokonts, are a clade of organisms distinguished by the presence of stiff tripartite external hairs. In most species, the hairs are attached to flagella, in some they are attached to other areas of the cellular surface, and in some they have been secondarily lost (in which case relatedness to stramenopile ancestors is evident from other shared cytological features or from genetic similarity). Stramenopiles represent one of the three major clades in the SAR supergroup, along with Alveolata and Rhizaria.
Stramenopiles are eukaryotes; most are single-celled, but some are multicellular including some large seaweeds, the brown algae. The group includes a variety of algal protists, heterotrophic flagellates, opalines and closely related proteromonad flagellates (all endobionts in other organisms); the actinophryid heliozoa, and oomycetes. The tripartite hairs characteristic of the group have been lost in some of the included taxa – for example in most diatoms. (Full article...)
... that the woodland garden, "colourfully planted with exotic shrubs and herbaceous plants, dominated English horticulture from 1910 to 1960"?
... that plant biology professor Luca Comai independently developed glyphosate-resistant plants while working at Calgene and published his research before Monsanto researchers were able to?
... that New York City's Bartow–Pell Mansion became a museum after its operator was restricted from importing and exporting plants?
Image 2The 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 3A 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 4Five of the key areas of study within plant physiology (from Botany)
Image 15The 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 16Transverse section of a fossil stem of the Devonian vascular plant Rhynia gwynne-vaughani (from Botany)
Image 19Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification; here, the specific name glauca means blue. (from Botany)
Image 20The 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 21The Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale. (from Botany)
Image 23The 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 24A 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 311 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 36Structure 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)
Image 37The branching pattern of megaphyll veins may indicate their origin as webbed, dichotomising branches. (from Evolutionary history of plants)