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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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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Banksia verticillata, commonly known as granite banksia or Albany banksia, is a species of shrub or (rarely) tree of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 3 m (10 ft) in height. It can grow taller to 5 m (16 ft) in sheltered areas, and much smaller in more exposed areas. This species has elliptic green leaves and large, bright golden yellow inflorescences or flower spikes, appearing in summer and autumn. The New Holland honeyeater (Phylidonyris novaehollandiae) is the most prominent pollinator, although several other species of honeyeater, as well as bees, visit the flower spikes.
A declared vulnerable species, it occurs in two disjunct populations on granite outcrops along the south coast of Western Australia, with the main population near Albany and a smaller population near Walpole, and is threatened by dieback (Phytophthora cinnamomi) and aerial canker (Zythiostroma). B. verticillata is killed by bushfire and new plants regenerate from seed afterwards. Populations take over a decade to produce seed and fire intervals of greater than twenty years are needed to allow the canopy seed bank to accumulate. (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...)
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Telopea speciosissima flowerhead with florets opening from the edges towards the centre, Blue Mountains, Australia
The floral emblem for its home state of New South Wales, Telopea speciosissima has featured prominently in art, architecture, and advertising, particularly since Australian federation. Commercially grown in several countries as a cut flower, it is also cultivated in home gardens, requiring good drainage yet adequate moisture, but is vulnerable to various fungal diseases and pests. A number of cultivars with various shades of red, pink and even white flowers are available. Horticulturists have also developed hybrids with T. oreades and T. mongaensis which are more tolerant of cold, shade, and heavier soils. (Full article...)
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Epacris impressa, also known as common heath, is a species of plant in the heath family Ericaceae. It is native to south-eastern Australia (the states of Victoria, Tasmania, South Australia and New South Wales). French botanist Jacques Labillardière collected the species in 1793 and described it in 1805. Four forms have been identified, but no subspecies are recognised. Growing in heathland, shrubland or open forest, it is generally a small shrub around 0.5 to 1 m (1 ft 8 in to 3 ft 3 in) tall, with small stiff leaves. The red, pink or white tube-like flowers appear from late autumn to early spring. Honeyeater birds, particularly the eastern spinebill, feed upon the nectar of the flowers. It regenerates after bushfire by seed or by resprouting.
A highly regarded garden plant, the common heath was first cultivated in England in 1825; over seventy named cultivars have been developed, most of which have now vanished. A pink-flowered form, often referred to as "pink heath", is the floral emblem of the state of Victoria. Epacris impressa has proven a difficult plant to propagate reliably, which has limited its use in horticulture and revegetation. It grows best in well-drained but moist soil in a semishaded position. (Full article...)
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Cucurbita fruits come in an assortment of colors and sizes.
Cucurbita (Latin for 'gourd') is a genus of herbaceousfruits in the gourd family, Cucurbitaceae (also known as cucurbits or cucurbi), native to the Andes and Mesoamerica. Five edible species are grown and consumed for their flesh and seeds. They are variously known as squash, pumpkin, or gourd, depending on species, variety, and local parlance. Other kinds of gourd, also called bottle-gourds, are native to Africa and belong to the genus Lagenaria, which is in the same family and subfamily as Cucurbita, but in a different tribe. These other gourds are used as utensils or vessels, and their young fruits are eaten much like those of the Cucurbita species.
Most Cucurbita species are herbaceous vines that grow several meters in length and have tendrils, but non-vining "bush" cultivars of C. pepo and C. maxima have also been developed. The yellow or orange flowers on a Cucurbita plant are of two types: female and male. The female flowers produce the fruit and the male flowers produce pollen. Many North and Central American species are visited by specialist beepollinators, but other insects with more general feeding habits, such as honey bees, also visit. (Full article...)
Banksia coccinea, commonly known as the scarlet banksia, waratah banksia or Albany banksia, is an erect shrub or small tree in the familyProteaceae. Its distribution in the wild is along the southwest coast of Western Australia, from Denmark to the Stokes National Park, and north to the Stirling Range, growing on white or grey sand in shrubland, heath or open woodland. Reaching up to 8 m (26 ft) in height, it is a single-stemmed plant that has oblong leaves, which are 3–9 cm (1.2–3.5 in) long and 2–7 cm (0.8–2.8 in) wide. The prominent red and white flower spikes appear mainly in the spring. As they age they develop small follicles that store seeds until opened by fire. Though widely occurring, it 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, Banksia coccinea appears to be most closely related to Banksia speciosa and B. baxteri. Banksia coccinea plants are killed by bushfire, and regenerate from seed. The flowers attract nectar- and insect-feeding birds, particularly honeyeaters, and a variety of insects. Widely considered one of the most attractive Banksia species, B. coccinea is a popular garden plant and one of the most important Banksia species for the cut flower industry; it is grown commercially in several countries including Australia, South Africa, Canada, the United States, New Zealand and Israel. In cultivation, B. coccinea grows well in a sunny location on well-drained soil, but it cannot survive in areas with humid or wet summers. (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...)
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...)
The species was first collected by Humboldt and Bonpland on the outskirts of Mina de Morán in the Sierra de Pachuca of the modern-day Mexican state of Hidalgo on their Latin American expedition of 1799–1804. Based on these collections, Carl Sigismund Kunth described this species in Nova Genera et Species Plantarum in 1817. The extremely variable species has been redefined at least twice since, while several new species have been segregated from it based on various geographical or morphological distinctions, although the legitimacy of some of these is still debated. P. moranensis remains the most common and most widely distributed member of the Section Orcheosanthus. It has long been cultivated for its carnivorous nature and attractive flowers, and is one of the most common butterworts in cultivation. (Full article...)
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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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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...)
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Alloxylon flammeum, commonly known as the Queensland tree waratah or red silky oak, is a medium-sized tree of the family Proteaceae found in the Queensland tropical rain forests of northeastern Australia. It has shiny green elliptical leaves up to 18 cm (7.1 in) long, and prominent orange-red inflorescences that appear from August to October, followed by rectangular woody seed pods that ripen in February and March. Juvenile plants have large (up to 25 cm (9.8 in) long) deeply lobed pinnate leaves. Previously known as Oreocallis wickhamii, the initial specimen turned out to be a different species to the one cultivated and hence a new scientific name was required. Described formally by Peter Weston and Mike Crisp in 1991, A. flammeum was designated the type species of the genus Alloxylon. This genus contains the four species previously classified in Oreocallis that are found in Australasia.
Alloxylon flammeum is a canopy or emergent tree of the Mabi rainforest community of north Queensland. Its terminal tubular flowers indicate that the species is pollinated by birds. Readily adaptable to cultivation, Alloxylon flammeum prefers a site with good drainage and responds well to extra moisture and fertilisers low in phosphorus. It is listed nationally as vulnerable under the Australian Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) as most of its habitat has been cleared for agriculture and logging. (Full article...)
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Adenanthos obovatus, commonly known as basket flower (which usually refers to Centaurea, though), or, jugflower, is a shrub of the plantfamilyProteaceaeendemic to Southwest Australia. Described by French naturalist Jacques Labillardière in 1805, it had first been collected by Archibald Menzies in 1791. Within the genus Adenanthos, it lies in the sectionEurylaema and is most closely related to A. barbiger. A. obovatus has hybridized with A. detmoldii to produce the hybrid A. × pamela. Several common names allude to the prominent red flowers of the species. It grows as a many-stemmed spreading bush up to 1 m (3.3 ft) high, and about 1.5 m (4.9 ft) across, with fine bright green foliage. Made up of single red flowers, the inflorescences appear from April to December, and peak in spring (August to October).
The shrub grows on sandy soils in seasonally wet lowland areas as well as hills and dunes. It regenerates after bushfire by resprouting from its underground lignotuber. Pollinators include honeyeaters, particularly the western spinebill, which can access the nectar with its long curved bill, and the silvereye, which punctures the flower tube. The most commonly cultivated Adenanthos species in Australia, it has a long flowering period and attracts honeyeaters to the garden. It is harvested for the cut flower industry. (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...)
A horticulture student tending to plants in a garden in Lawrenceville, Georgia, March 2015 Horticulture is the art and science of growing plants. This definition is seen in its etymology, which is derived from the Latin words hortus, which means "garden" and cultura which means "to cultivate". There are various divisions of horticulture because plants are grown for a variety of purposes. These divisions include, but are not limited to: gardening, plant production/propagation, arboriculture, landscaping, floriculture and turf maintenance. For each of these, there are various professions, aspects, tools used and associated challenges; Each requiring highly specialized skills and knowledge of the horticulturist.
Typically, horticulture is characterized as the ornamental, small-scale/non-industrial cultivation of plants, as compared to the large-scale cultivation of crops/livestock that is seen in agriculture. However, there are aspects of horticulture that are industrialized/commercial such as greenhouse production across the globe. (Full article...)
The name "ragweed" is derived from "ragged" + "weed," coming from the ragged appearance of the plant's leaves. Other common names include bursages and burrobrushes. The genus name is from the Greekambrosia, meaning "food or drink of immortality". (Full article...)
The family has a cosmopolitan distribution. The enlarged Lamiaceae contain about 236 genera and have been stated to contain 6,900 to 7,200 species, but the World Checklist lists 7,534. The largest genera are Salvia (900), Scutellaria (360), Stachys (300), Plectranthus (300), Hyptis (280), Teucrium (250), Vitex (250), Thymus (220), and Nepeta (200). Clerodendrum was once a genus of over 400 species, but by 2010, it had been narrowed to about 150. (Full article...)
The common commercial variety is called the California Blackeye; it is pale-colored with a prominent black spot. The American South has countless varieties, many of them heirloom, that vary in size from the small lady peas to very large ones. The color of the eye may be black, brown, red, pink, or green. All the peas are green when freshly shelled and brown or buff when dried. A popular variation of the black-eyed pea is the purple hull pea or mud-in-your-eye pea; it is usually green with a prominent purple or pink spot. The currently accepted botanical name for the black-eyed pea is Vigna unguiculata subsp. unguiculata, although previously it was classified in the genusPhaseolus. Vigna unguiculata subsp. dekindtiana is the wild relative and Vigna unguiculata subsp. sesquipedalis is the related asparagus bean. Other beans of somewhat similar appearance, such as the frijol ojo de cabra (goat's-eye bean) of northern Mexico, are sometimes incorrectly called black-eyed peas, and vice versa. (Full article...)
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Close-up of a flower of Schlumbergera (Christmas or Holiday Cactus), showing part of the gynoecium (the stigma and part of the style is visible) and the stamens that surround it
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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Simplified photorespiration cycle
Photorespiration (also known as the oxidative photosynthetic carbon cycle or C2 cycle) refers to a process in plant metabolism where the enzymeRuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. The desired reaction is the addition of carbon dioxide to RuBP (carboxylation), a key step in the Calvin–Benson cycle, but approximately 25% of reactions by RuBisCO instead add oxygen to RuBP (oxygenation), creating a product that cannot be used within the Calvin–Benson cycle. This process lowers the efficiency of photosynthesis, potentially lowering photosynthetic output by 25% in C3 plants. Photorespiration involves a complex network of enzyme reactions that exchange metabolites between chloroplasts, leaf peroxisomes and mitochondria.
The oxygenation reaction of RuBisCO is a wasteful process because 3-phosphoglycerate is created at a lower rate and higher metabolic cost compared with RuBP carboxylase activity. While photorespiratory carbon cycling results in the formation of G3P eventually, around 25% of carbon fixed by photorespiration is re-released as CO2 and nitrogen, as ammonia. Ammonia must then be detoxified at a substantial cost to the cell. Photorespiration also incurs a direct cost of one ATP and one NAD(P)H. (Full article...)
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Tropical coastline vegetation in Maui with Scaevola taccada bush in the foreground Tropical vegetation is any vegetation in tropicallatitudes. Plant life that occurs in climates that are warm year-round is in general more biologically diverse that in other latitudes. Some tropical areas may receive abundant rain the whole year round, but others have long dry seasons which last several months and may vary in length and intensity with geographic location. These seasonal droughts have great impact on the vegetation, such as in the Madagascar spiny forests.
Rainforest vegetation is categorized by five layers. The top layer being the upper tree layer. Here you will find the largest and widest trees in all the forest. These trees tend to have very large canopy's so they can be fully exposed to sunlight. A layer below that is the middle tree layer. Here you will find more compact trees and vegetation. These trees tend to be more skinny as they are trying to gain any sunlight they can. The third layer is the lower tree area. These trees tend to be around five to ten meters high and tightly compacted. The trees found in the third layer are young trees trying to grow into the larger canopy trees. The fourth layer is the shrub layer beneath the tree canopy. This layer is mainly populated by sapling trees, shrubs, and seedlings. The fifth and final layer is the herb layer which is the forest floor. The forest floor is mainly bare except for various plants, mosses, and ferns. The forest floor is much more dense than above because of little sunlight and air movement. (Full article...)
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Various gymnosperms.
The gymnosperms (/ˈdʒɪmnəˌspɜːrmz,-noʊ-/ⓘJIM-nə-spurmz, -noh-; lit.'revealed seeds') are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae. The term gymnosperm comes from the composite word in Greek: γυμνόσπερμος (γυμνός, gymnos, 'naked' and σπέρμα, sperma, 'seed'), literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or on their own as in yew, Torreya, Ginkgo. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploidsporophyte phase and a reduced haploidgametophyte phase which is dependent on the sporophytic phase. The term "gymnosperm" is often used in paleobotany to refer to (the paraphyletic group of) all non-angiosperm seed plants. In that case, to specify the modern monophyletic group of gymnosperms, the term Acrogymnospermae is sometimes used.
The gymnosperms and angiosperms together constitute the spermatophytes or seed plants. The spermatophytes are subdivided into five divisions, the angiosperms and four divisions of gymnosperms: the Cycadophyta, Ginkgophyta, Gnetophyta, and Pinophyta (also known as Coniferophyta). Newer classification place the gnetophytes among the conifers. Numerous extinct seed plant groups are recognised including those considered pteridosperms/seed ferns, as well other groups like the Bennettitales. (Full article...)
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Cotyledon from a Judas-tree (Cercis siliquastrum, a dicot) seedling A cotyledon (/ˌkɒtɪˈliːdən/; from Latincotyledon; from κοτυληδών (kotulēdṓn) "a cavity, small cup, any cup-shaped hollow", gen. κοτυληδόνος (kotulēdónos), from κοτύλη (kotýlē) 'cup, bowl') is a "seed leaf" - a significant part of the embryo within the seed of a plant, and is formally defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." Botanists use the number of cotyledons present as one characteristic to classify the flowering plants (angiosperms): species with one cotyledon are called monocotyledonous ("monocots"); plants with two embryonic leaves are termed dicotyledonous ("dicots").
In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons form during embryogenesis, along with the root and shoot meristems, and are therefore present in the seed prior to germination. True leaves, however, form post-embryonically (i.e. after germination) from the shoot apical meristem, which generates subsequent aerial portions of the plant. (Full article...)
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Jean H. Langenheim (née Harmon; September 5, 1925 – March 28, 2021) was an American plant ecologist and ethnobotanist, highly respected as an eminent scholar and a pioneer for women in the field. She has done field research in arctic, tropical, and alpine environments across five continents, with interdisciplinary research that spans across the fields of chemistry, geology, and botany. Her early research helped determine the plant origins of amber and led to her career-long work investigating the chemical ecology of resin-producing trees, including the role of plant resins for plant defense and the evolution of several resin-producing trees in the tropics. She wrote what is regarded as the authoritative reference on the topic: Plant Resins: Chemistry, Evolution, Ecology, and Ethnobotany, published in 2003.
Langenheim earned a PhD in botany with a minor in geology in 1953 from the University of Minnesota. She was the first female faculty member in the natural sciences and first woman to be promoted to full professor at the University of California, Santa Cruz. She was the first woman to serve as president for the Association for Tropical Biology, second woman to serve as president of the Ecological Society of America (ESA) and Society for Economic Botany, founded and served as the first president for the International Society of Chemical Ecology, and was a fellow of the American Association for the Advancement of Science and the California Academy of Sciences. During her time as ESA president, she initiated a project to document women's experiences and contributions to the field of ecology and conducted a follow-up project in 1996. Her research was summarized in two publications, and resulted in a large historical collection and a continued effort by ESA to document women's contributions to the field. (Full article...)
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Three soil scientists examining a farm land sample Plant nutrition is the study of the chemical elements and compounds necessary for plant growth and reproduction, plant metabolism and their external supply. In its absence the plant is unable to complete a normal life cycle, or that the element is part of some essential plant constituent or metabolite. This is in accordance with Justus von Liebig'slaw of the minimum. The total essential plant nutrients include seventeen different elements: carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil (exceptions include some parasitic or carnivorous plants).
Plants must obtain the following mineral nutrients from their growing medium:
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...)
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The Chinese character for hemp (麻 or má) depicts two plants under a shelter. Notably, the same character also means "numb". Cannabis cultivation dates back at least 3000 years in Taiwan.
The history of cannabis and its usage by humans dates back to at least the third millennium BC in written history, and possibly as far back as the Pre-Pottery Neolithic B (8800–6500 BCE) based on archaeological evidence. For millennia, the plant has been valued for its use for fiber and rope, as food and medicine, and for its psychoactive properties for religious and recreational use.
The earliest restrictions on cannabis were reported in the Islamic world by the 14th century. In the 19th century, it began to be restricted in colonial countries, often associated with racial and class stresses. In the middle of the 20th century, international coordination led to sweeping restrictions on cannabis throughout most of the globe. Entering the 21st century, some nations began to take measures to decriminalize or legalize cannabis. (Full article...)
Date palms reach up to 30 metres (100 feet) in height, growing singly or forming a clump with several stems from a single root system. Slow-growing, they can reach over 100years of age when maintained properly. Date fruits (dates) are oval-cylindrical, 3 to 7 centimetres (1 to 3 inches) long, and about 2.5 cm (1 in) in diameter, with colour ranging from dark brown to bright red or yellow, depending on variety. Containing 61–68percent sugar by mass when dried, dates are very sweet and are enjoyed as desserts on their own or within confections. (Full article...)
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Evolutionary developmental biology (evo-devo) is the study of developmental programs and patterns from an evolutionary perspective. It seeks to understand the various influences shaping the form and nature of life on the planet. Evo-devo arose as a separate branch of science rather recently. An early sign of this occurred in 1999.
Grandidier's baobab (Adansonia grandidieri) is the biggest and most famous of Madagascar's six baobab species. It has a massive cylindrical trunk, up to 3 m (9.8 ft) across, and can reach up to 25 m (82 ft) in height. The large, dry fruits of the baobab contain kidney-shaped seeds within an edible pulp. It is named after the French botanist and explorer Alfred Grandidier, who documented many of the animals and plants of Madagascar.
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In mathematics, the three-gap theorem, three-distance theorem, or Steinhaus conjecture states that if one places n points on a circle, at angles of θ, 2θ, 3θ, ... from the starting point, then there will be at most three distinct distances between pairs of points in adjacent positions around the circle. When there are three distances, the largest of the three always equals the sum of the other two. Unless θ is a rational multiple of π, there will also be at least two distinct distances.
This result was conjectured by Hugo Steinhaus, and proved in the 1950s by Vera T. Sós, János Surányi [hu], and Stanisław Świerczkowski; more proofs were added by others later. Applications of the three-gap theorem include the study of plant growth and musical tuning systems, and the theory of light reflection within a mirrored square. (Full article...)
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Carex binervis, the green-ribbed sedge, is a European species of sedge with an Atlantic distribution. It is found from Fennoscandia to the Iberian Peninsula, and occurs in heaths, moorland and other damp, acidic environments. It typically grows to a height of 15–120 cm (6–50 in), and has inflorescences comprising one male and several female spikes, each up to 45 mm (1.8 in) long. The utricles have two conspicuous green veins, which give rise to both the scientific name and the common name of the species. In the vegetative state, it closely resembles C. bigelowii, a species that usually grows at higher altitude. C. binervis was first described by James Edward Smith in 1800, and is classified in Carex sect. Spirostachyae; several hybrids with other Carex species are known. (Full article...)
The taxonomy of Narcissus is complex, and still not fully resolved. Known to the ancients, the genus name appears in Graeco-Roman literature, although their interest was as much medicinal as botanical. It is unclear which species the ancients were familiar with. Although frequently mentioned in Mediaeval and Renaissance texts it was not formally described till the work of Linnaeus in 1753. By 1789 it had been grouped into a family (Narcissi) but shortly thereafter this was renamed Amaryllideae, from which comes the modern placement within Amaryllidaceae, although for a while it was considered part of Liliaceae.
Many of the species now considered to be Narcissus were in separate genera during the nineteenth century, and the situation was further confused by the inclusion of many cultivated varieties. By 1875 the current circumscription was relatively settled. By 2004 phylogenetic studies had allowed the place of Narcissus within its fairly large family to be established, nested within a series of subfamilies (Amaryllidoideae) and tribes (Narcisseae). It shares its position in the latter tribe with Sternbergia. (Full article...)
Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, leaves, roots, and seeds. An alternative definition of the term is applied somewhat arbitrarily, often by culinary and cultural tradition. It may exclude foods derived from some plants that are fruits, flowers, nuts, and cereal grains, but include savoury fruits such as tomatoes and courgettes, flowers such as broccoli, and seeds such as pulses.
Originally, vegetables were collected from the wild by hunter-gatherers and entered cultivation in several parts of the world, probably during the period 10,000 BC to 7,000 BC, when a new agricultural way of life developed. At first, plants that grew locally were cultivated, but as time went on, trade brought common and exotic crops from elsewhere to add to domestic types. Nowadays, most vegetables are grown all over the world as climate permits, and crops may be cultivated in protected environments in less suitable locations. China is the largest producer of vegetables, and global trade in agricultural products allows consumers to purchase vegetables grown in faraway countries. The scale of production varies from subsistence farmers supplying the needs of their family for food, to agribusinesses with vast acreages of single-product crops. Depending on the type of vegetable concerned, harvesting the crop is followed by grading, storing, processing, and marketing. (Full article...)
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Hypericum aegypticum is a species of flowering plant of the St. John's wort family (Hypericaceae) which is native to the Eastern Mediterranean. It was described by Carl Linnaeus in the second volume of his Species Plantarum in 1753, who named it after Egypt despite it not being distributed there. The plant is commonly known as shrubby St. John's wort or Egyptian St. John's wort in English. Like other members of section Adenotrias, it is found among limestone rocks in coastal areas. While it has been evaluated as threatened on the island of Malta, the species has no legal protections.
The species is a shrub or shrublet that grows up to 2 meters (6.5 feet) tall with many branches, each having a single small flower with five yellow petals and many stamens. Its leaves lack hairs, and have densely patterned glands and large primary veins. The species is notable for its heterostyly, a trait which within the Hypericum genus is unique to section Adenotrias, and exhibits one of two heterostylous flower types called "pins" and "thrums". It has three subspecies, which vary in their distribution and phytochemical makeup. (Full article...)
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Hypericum × inodorum 'Golden Beacon' in Belgium
Hypericum × inodorum, called tall tutsan or the tall St John's wort, is a bushy perennialshrub with yellow flowers native to Western Europe. It has been known since 1789, but confusion around its name, identity, and origin persisted throughout the 19th and 20th centuries.
The 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. Botany, also called plant science (or plant sciences), plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word βοτάνη (botanē) meaning "pasture", "herbs" "grass", or "fodder"; βοτάνη is in turn derived from βόσκειν (boskein), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists (in the strict sense) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants (including approximately 369,000 species of flowering plants), and approximately 20,000 are bryophytes.
Botany originated in prehistory as herbalism with the efforts of early humans to identify – and later cultivate – plants that were edible, poisonous, and possibly medicinal, making it one of the first endeavours of human investigation. Medieval physic gardens, often attached to monasteries, contained plants possibly having medicinal benefit. They were forerunners of the first botanical gardens attached to universities, founded from the 1540s onwards. One of the earliest was the Padua botanical garden. These gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, and led in 1753 to the binomial system of nomenclature of Carl Linnaeus that remains in use to this day for the naming of all biological species. (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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Hypericum hircinum is a species of perennialflowering plant in the St John's wort family, Hypericaceae. It is known as goat St John's wort and stinking tutsan; both names refer to the plant's distinctive odor. The species is a bushy shrub that can grow up to 1.5 meters tall, is many-stemmed, and has golden yellow flowers with conspicuous stamens. The plant has been well-documented in botanical literature, with mentions dating back to at least 1627. Carl Linnaeus described H. hircinum several times, including in his 1753 Species Plantarum which established its binomial. At one point the plant was placed into the defunct genus Androsaemum, but it was returned to Hypericum by Norman Robson in 1985.
Hypericum hircinum is continuously distributed across the Mediterranean and parts of the Middle East. It has also been cultivated throughout Europe, and has become naturalized in several places where it escaped captivity. The species is highly variable in appearance, but its lack of geographic separation means that five subspecies have been established to account for its diversity. H. hircinum has been hybridized with the closely related H. androsaemum to produce the fertilenothospeciesH. × inodorum, which lacks the goat-like smell of H. hircinum. (Full article...)
Erythranthe, the monkey-flowers and musk-flowers, is a diverse plantgenus with more than 120 members (as of 2022) in the familyPhrymaceae. Erythranthe was originally described as a separate genus, then generally regarded as a section within the genus Mimulus, and recently returned to generic rank. Mimulus sect. Diplacus was segregated from Mimulus as a separate genus at the same time. Mimulus remains as a small genus of eastern North America and the Southern Hemisphere. Molecular data show Erythranthe and Diplacus to be distinct evolutionary lines that are distinct from Mimulus as strictly defined, although this nomenclature is controversial.
Member species are usually annuals or herbaceousperennials. Flowers are red, pink, or yellow, often in various combinations. A large number of the Erythranthe species grow in moist to wet soils with some growing even in shallow water. They are not very drought resistant, but many of the species now classified as Diplacus are. Species are found at elevations from oceanside to high mountains as well as a wide variety of climates, though most prefer wet areas such as riverbanks. (Full article...)
A cereal is a grass cultivated for its edible grain. Cereals are the world's largest crops, and are therefore staple foods. They include rice, wheat, rye, oats, barley, millet, and maize. Edible grains from other plant families, such as buckwheat and quinoa are pseudocereals. Most cereals are annuals, producing one crop from each planting, though rice is sometimes grown as a perennial. Winter varieties are hardy enough to be planted in the autumn, becoming dormant in the winter, and harvested in spring or early summer; spring varieties are planted in spring and harvested in late summer. The term cereal is derived from the name of the Roman goddess of grain crops and fertility, Ceres.
Utricularia inflata, commonly known as the swollen bladderwort, inflated bladderwort, or large floating bladderwort, is a large suspended aquatic carnivorous plant that belongs to the genusUtricularia. It is a perennial that is native to the southeastern coastal plains of the United States. It has often been confused with U. radiata, which is similar but smaller than U. inflata. Since 1980, U. inflata has been reported to exist in locations beyond its traditional range, such as the Adirondack Mountains in New York, southeastern Massachusetts, and in Washington State. Studies on the populations in the Adirondacks suggest that an introduction of U inflata. to a location where it naturalizes can lead to altered sediment chemistry by reducing the net primary productivity of native species. It is also listed by the state of Washington as a problematic species because of the dense mat-forming habit of this aquatic Utricularia. It is one of the few carnivorous plants that can be invasive. (Full article...)
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Mature kahikatea tree
Dacrycarpus dacrydioides, commonly known as kahikatea (from Māori) and white pine, is a coniferous tree endemic to New Zealand. A podocarp, it is New Zealand's tallest tree, gaining heights of 60 m over a life span of 600 years. It was first described botanically by the French botanist Achille Richard in 1832 as Podocarpusdacrydioides, and was given its current binomial nameDacrycarpus dacrydioides in 1969 by the American botanist David de Laubenfels. Analysis of DNA has confirmed its evolutionary relationship with other species in the genera Dacrycarpus and Dacrydium.
In Māori culture, it is an important source of timber for the building of waka and making of tools, of food in the form of its berries, and of dye. Its use for timber and its damp fertile habitat, ideal for dairy farming, have led to its decimation almost everywhere except South Westland. (Full article...)
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Hyacinthoides non-scripta/ˌhaɪəsɪnˈθɔɪdiːznɒnˈskrɪptə/ (formerly Endymion non-scriptus or Scilla non-scripta) is a bulbousperennial plant found in Atlantic areas from the north-western part of the Iberian Peninsula to the British Isles, and also frequently used as a garden plant. It is known in English as the common bluebell or simply bluebell, a name which is used in Scotland to refer to the harebell, Campanula rotundifolia. In spring, H. non-scripta produces a nodding, one-sided inflorescence of 5–12 tubular, sweet-scented violet–blue flowers, with strongly recurved tepals, and 3–6 long, linear, basal leaves.
H. non-scripta is particularly associated with ancient woodland where it may dominate the understorey to produce carpets of violet–blue flowers in "bluebell woods", but also occurs in more open habitats in western regions. It is protected under UK law, and in some other parts of its range. A related species, H. hispanica has also been introduced to Britain and Ireland and hybridises with H. non-scripta to produce intermediates known as H. × massartiana. (Full article...)
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Dracophyllum arboreum, commonly known as Chatham Island grass tree and tarahinau (Moriori), is a species of tree in the heath family Ericaceae. Endemic to the Chatham Islands of New Zealand, it reaches a height of 18 m (60 ft) and has leaves that differ between the juvenile and adult forms.
D. arboreum has wide light green leaves in its juvenile form, which become thin needles as it gains maturity. Flowering occurs from November through to February, yielding small white flowers which later become tiny brown fruit. It inhabits many different types of vegetation communities from near sea level to 270 m (886 ft), including swamps, cliffs, bogs, and shrublands. It has a range restricted to three Islands some 800 km (497 mi) east of New Zealand: the Chatham, Pitt, and Rangatira Islands. (Full article...)
... that Marie Catharine Neal, an expert on Hawaiian plants, authored the acclaimed book In Gardens of Hawaii in 1948, which described more than 2,000 species with detailed scientific information and illustrations?
... that ochrophyte algae have twice as many membranes around their chloroplasts as plants?
... that police officers had to be flown in by helicopter to seize hundreds of thousands of dollars' worth of cannabis plants found growing illegally in Jerrawangala National Park?
... that campaigning by climate activist Kimiko Hirata halted plans to build 17 new coal-fired power plants following the Fukushima nuclear disaster in Japan?
... that blind botanist John Grimshaw Wilkinson used his tongue to tell the difference between plants?
Image 3A botanist preparing a plant specimen for mounting in the herbarium (from Botany)
Image 4Leaf lamina. The megaphyllous leaf architecture arose multiple times in different plant lineages (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 6The 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 7Five of the key areas of study within plant physiology (from Botany)
Image 8Thale cress, Arabidopsis thaliana, the first plant to have its genome sequenced, remains the most important model organism. (from Botany)
Image 91 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 10A 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 20Structure 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 24Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification; here, the specific name glauca means blue. (from Botany)
Image 26Structure of a plant cell (from Plant cell)
Image 27The food we eat comes directly or indirectly from plants such as rice. (from Botany)
Image 28The 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 29Transverse section of a fossil stem of the Devonian vascular plant Rhynia gwynne-vaughani (from Botany)
Image 30A 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 31The Linnaean Garden of Linnaeus' residence in Uppsala, Sweden, was planted according to his Systema sexuale. (from Botany)
Image 37The 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)
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