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.
Image 1
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...)
Banksia paludosa, commonly known as the marsh or swamp banksia, is a species of shrub in the plantgenusBanksia. It is native to New South Wales, Australia, where it is found between Sydney and Batemans Bay, with an isolated population further south around Eden. There are two recognised subspecies, the nominate of which is a spreading shrub to 1.5 m (4.9 ft) in height, and subsp. astrolux is a taller shrub to 5 m (16 ft) high found only in Nattai National Park.
Native mammals, such as the brown antechinus and sugar glider, are important pollinators of B. paludosa. Several species of honeyeaters visit the flower spikes, as do ants and the European honey bee. The response to bushfire depends on the subspecies; subspecies paludosa regenerates from underground lignotubers, while plants of subspecies astrolux are killed by fire and regenerate from large stores of seed which have been held in cones in the plant canopy. B. paludosa is sometimes seen in cultivation, with dwarf forms being registered and sold. (Full article...)
Image 3
Banksia prionotes, commonly known as acorn banksia or orange banksia, is a species of shrub or tree of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 10 m (33 ft) in height. It can be much smaller in more exposed areas or in the north of its range. This species has serrated, dull green leaves and large, bright flower spikes, initially white before opening to a bright orange. Its common name arises from the partly opened inflorescence, which is shaped like an acorn. The tree is a popular garden plant and also of importance to the cut flower industry.
Banksia prionotes was first described in 1840 by English botanist John Lindley, probably from material collected by James Drummond the previous year. There are no recognised varieties, although it has been known to hybridise with Banksia hookeriana. Widely distributed in south-west Western Australia, B. prionotes is found from Shark Bay (25° S) in the north, south as far as Kojonup (33°50′S). It grows exclusively in sandy soils, and is usually the dominant plant in scrubland or low woodland. Pollinated by birds, it provides food for a wide array of vertebrate and invertebrate animals in the autumn and winter months. It is an important source of food for honeyeaters (Meliphagidae), and is critical to their survival in the Avon Wheatbelt region, where it is the only nectar-producing plant in flower at some times of the year. (Full article...)
Image 4
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...)
Image 5
Adiantum viridimontanum growing in a dunite roadcut
Adiantum viridimontanum, commonly known as Green Mountain maidenhair fern, is a fern found only in outcrops of serpentine rock in New England and Eastern Canada. The leaf blade is cut into finger-like segments, themselves once-divided, which are borne on the outer side of a curved, dark, glossy rachis. These finger-like segments are not individual leaves, but parts of a single compound leaf. The "fingers" may be drooping or erect, depending on whether the individual fern grows in shade or sunlight. Spores are borne under false indusia at the edge of the subdivisions of the leaf, a characteristic unique to the genus Adiantum.
Until 1991, A. viridimontanum was grouped with the western maidenhair fern, A. aleuticum, which grows both in western North America and as a disjunct on serpentine outcrops in eastern North America. At one time, A. aleuticum itself was classified as a variety (A. pedatum var. aleuticum) of the northern maidenhair fern, A. pedatum. However, after several years of study, botanist Cathy Paris recognized that A. aleuticum was a distinct species, and that some of the specimens that had been attributed to that taxon (group of organisms) were a third, hybrid species intermediate between A. pedatum and A. aleuticum. She named the new species A. viridimontanum for the site of its discovery in the Green Mountains in Vermont; it has since been located in Quebec and in one site in coastal Maine. (Full article...)
Image 6
Banksia cuneata, commonly known as matchstick banksia or Quairading banksia, is an endangered species of flowering plant in the family Proteaceae. Endemic to southwestWestern Australia, it belongs to Banksia subg. Isostylis, a sub-genus of three closely related Banksia species with inflorescences or flower clusters that are dome-shaped heads rather than characteristic Banksia flower spikes. A shrub or small tree up to 5 m (16 ft) high, it has prickly foliage and pink and cream flowers. The common name Matchstick Banksia arises from the blooms in late bud, the individual buds of which resemble matchsticks. The species is pollinated by honeyeaters (Meliphagidae).
Although B. cuneata was first collected before 1880, it was not until 1981 that Australian botanist Alex George formally described and named the species. There are two genetically distinct population groups, but no recognised varieties. This Banksia is classified as endangered, surviving in fragments of remnant bushland in a region which has been 93% cleared for agriculture. As Banksia cuneata is killed by fire and regenerates from seed, it is highly sensitive to bushfire frequency—fires recurring within four years could wipe out populations of plants not yet mature enough to set seed. Banksia cuneata is rarely cultivated, and its prickly foliage limits its utility in the cut flower industry. (Full article...)
Banksia integrifolia, commonly known as the coast banksia, is a species of tree that grows along the east coast of Australia. One of the most widely distributed Banksia species, it occurs between Victoria and Central Queensland in a broad range of habitats, from coastal dunes to mountains. It is highly variable in form, but is most often encountered as a tree up to 25 metres (82 ft) in height. Its leaves have dark green upper surfaces and white undersides, a contrast that can be striking on windy days.
Banksia canei, commonly known as the mountain banksia, is a species of shrub that is endemic to southeastern Australia. It is generally encountered as a many-branched shrub that grows up to 3 m (10 ft) high, with narrow leaves and the yellow inflorescences (flower spikes) appearing from late summer to early winter. The old flowers fall off the spikes and up to 150 finely furred follicles develop, which remain closed until burnt in a bushfire. Each follicle bears two winged seeds. Response to fire is poorly known, although it is thought to regenerate by seed. Birds such as the yellow-tufted honeyeater and various insects forage among the flower spikes. It is frost tolerant in cultivation, but copes less well with aridity or humidity and is often short-lived in gardens. One cultivar, Banksia 'Celia Rosser', was registered in 1978, but has subsequently vanished.
Although no subspecies are recognised, four topodemes (geographically isolated populations) have been described, as there is significant variation in the shape of both adult and juvenile leaves between populations. Although superficially resembling B. marginata, it is more closely related to another subalpine species, B. saxicola. (Full article...)
Image 10
Banksia dentata, commonly known as the tropical banksia, is a species of tree in the family Proteaceae. It occurs across northern Australia, southern New Guinea and the Aru Islands. Growing as a gnarled tree to 7 m (23 ft) high, it has large green leaves up to 22 cm (8.7 in) long with dentatemargins. The cylindrical yellow inflorescences, up to 13 cm (5.1 in) high, appear between November and May, attracting various species of honeyeaters, sunbirds, the sugar glider and a variety of insects. Flowers fall off the ageing spikes, which swell and develop follicles containing up to two viable seeds each.
Banksia dentata is one of four Banksia species collected by Sir Joseph Banks in 1770, and one of the four species published in 1782 as part of Carolus Linnaeus the Younger's original description of Banksia. Within the genus, it is classified in the seriesSalicinae, a group of species from Australia's eastern states. Genetic studies show it is a basal member within the group. Banksia dentata is found in tropical grassland known as savanna, and associated with Pandanus and Melaleuca. It regenerates from bushfire by regrowing from its woody base, known as a lignotuber. (Full article...)
Image 11
The flora of Madagascar consists of more than 12,000 species of plants, as well as a poorly known number of fungi and algae. Around 83% of Madagascar's vascular plants are found only on the island. These endemics include five plant families, 85% of the over 900 orchid species, around 200 species of palms, and such emblematic species as the traveller's tree, six species of baobab and the Madagascar periwinkle. The high degree of endemism is due to Madagascar's long isolation following its separation from the African and Indian landmasses in the Mesozoic, 150–160 and 84–91 million years ago, respectively. However, few plant lineages remain from the ancient Gondwanan flora; most extant plant groups immigrated via across-ocean dispersal well after continental break-up.
After its continental separation, Madagascar probably experienced a dry period, and tropical rainforest expanded only later in the Oligocene to Miocene when rainfall increased. Today, humid forests, including the lowland forests, are mainly found on the eastern plateau where abundant rainfall from the Indian Ocean is captured by an escarpment. A large part of the central highlands, in the sub-humid forests ecoregion, is today dominated by grasslands. They are widely seen as result of human landscape transformation but some may be more ancient. Grassland occurs in a mosaic with woodland and bushland, including tapia forest, and hard-leaved thickets on the high mountains. Dry forest and succulent woodland are found in the drier western part and grade into the unique spiny thicket in the southwest, where rainfall is lowest and the wet season shortest. Mangroves occur on the west coast, and a variety of wetland habitats with an adapted flora are found across the island. (Full article...)
Banksia spinulosa, the hairpin banksia, is a species of woody shrub, of the genus Banksia in the family Proteaceae, native to eastern Australia. Widely distributed, it is found as an understorey plant in open dry forest or heathland from Victoria to northern Queensland, generally on sandstone though sometimes also clay soils. It generally grows as a small shrub to 2 metres (7 ft) in height, though can be a straggly tree to 6 metres (20 ft). It has long narrow leaves with inflorescences which can vary considerably in coloration; while the spikes are gold or less commonly yellowish, the emergent styles may be a wide range of colours – from black, purple, red, orange or yellow.
Banksia spinulosa was named by James Edward Smith in England in 1793, after being collected by John White, most likely in 1792. He gave it the common name prickly-leaved banksia, though this has fallen out of use. With four currently recognised varieties, the species has had a complicated taxonomic history, with two varieties initially described as separate species in the early 19th century. A fourth, from the New England region, has only recently been described. However, there has been disagreement whether one, var. cunninghamii, is distinct enough to once again have specific status. The pre-eminent authority on Banksia, Alex George, concedes there is still more work to be done on the Banksia spinulosa complex. (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...)
Image 14
Persoonia linearis, commonly known as the narrow-leaved geebung, is a shrub native to New South Wales and Victoria in eastern Australia. It reaches 3 m (9.8 ft), or occasionally 5 m (16 ft), in height and has thick, dark grey papery bark. The leaves are, as the species name suggests, more or less linear in shape, and are up to 9 cm (3.5 in) long, and 0.1 to 0.7 cm (0.039 to 0.276 in) wide. The small yellow flowers appear in summer, autumn and early winter (December to July), followed by small green fleshy fruit known as drupes. Within the genus Persoonia, it is a member of the Lanceolata group of 58 closely related species. P. linearis interbreeds with several other species where they grow together.
Found in dry sclerophyll forest on sandstone-based nutrient-deficient soils, P. linearis is adapted to a fire-prone environment; the plants resprout epicormic buds from beneath their thick bark after bushfires. The fruit are consumed by vertebrates such as kangaroo, possums and currawongs. As with other members of the genus, P. linearis is rare in cultivation as it is very hard to propagate by seed or by cuttings, but once propagated, it adapts readily, preferring acidic soils with good drainage and at least a partly sunny aspect. (Full article...)
While at the bookshop, he was offered a position as a librarian at the Royal Horticultural Society in London (1933–1952). From there he moved to the Natural History Museum as a scientific officer in the botany department (1952–1976). After his retirement, he continued working there, writing, and serving on a number of professional bodies related to his work, including the Linnean Society, of which he became president. He also taught botany at Cambridge University as a visiting professor (1977–1983). (Full article...)
The fig is the edible fruit of Ficus carica, a species of small tree in the flowering plant family Moraceae, native to the Mediterranean region, together with western and southern Asia. It has been cultivated since ancient times and is now widely grown throughout the world. Ficus carica is the type species of the genus Ficus, containing over 800 tropical and subtropical plant species.
A fig plant is a small deciduous tree or large shrub growing up to 7–10 m (23–33 ft) tall, with smooth white bark. Its large leaves have three to five deep lobes. Its fruit (referred to as syconium, a type of multiple fruit) is tear-shaped, 3–5 cm (1–2 in) long, with a green skin that may ripen toward purple or brown, and sweet soft reddish flesh containing numerous crunchy seeds. The milky sap of the green parts is an irritant to human skin. In the Northern Hemisphere, fresh figs are in season from late summer to early autumn. They tolerate moderate seasonal frost and can be grown even in hot-summer continental climates. (Full article...)
Image 2
A phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phytochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap. The region of overlap is called a vegetation tension zone.
In traditional schemes, areas in phytogeography are classified hierarchically, according to the presence of endemic families, genera or species, e.g., in floral (or floristic, phytogeographic) zones and regions, or also in kingdoms, regions and provinces, sometimes including the categories empire and domain. However, some authors prefer not to rank areas, referring to them simply as "areas", "regions" (in a non hierarchical sense) or "phytochoria". (Full article...)
Image 3
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...)
Image 4
Redcurrants, a type of berry derived from a simple (one-locule) inferior ovary In botany, a berry is a fleshy fruit without a stone (pit) produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants (aubergines), persimmons and bananas, but exclude certain fruits that meet the culinary definition of berries, such as strawberries and raspberries. The berry is the most common type of fleshy fruit in which the entire outer layer of the ovary wall ripens into a potentially edible "pericarp". Berries may be formed from one or more carpels from the same flower (i.e. from a simple or a compound ovary). The seeds are usually embedded in the fleshy interior of the ovary, but there are some non-fleshy exceptions, such as Capsicum species, with air rather than pulp around their seeds.
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...)
A European honey bee pollinates a peach flower while collecting nectar. Pollination of fruit trees is required to produce seeds with surrounding fruit. It is the process of moving pollen from the anther to the stigma, either in the same flower or in another flower. Some tree species, including many fruit trees, do not produce fruit from self-pollination, so pollinizer trees are planted in orchards.
The pollination process requires a carrier for the pollen, which can be animal, wind, or human intervention (by hand-pollination or by using a pollen sprayer). Cross pollination produces seeds with a different genetic makeup from the parent plants; such seeds may be created deliberately as part of a selective breeding program for fruit trees with desired attributes. Trees that are cross-pollinated or pollinated via an insect pollinator produce more fruit than trees with flowers that just self-pollinate. In fruit trees, bees are an essential part of the pollination process for the formation of fruit. (Full article...)
The names catnip and catmint are derived from the intense attraction about two-thirds of cats have toward the plant (alternatives exist, such as valerian root and leaves). Catnip is also an ingredient in some herbal teas (or tisanes), and is valued for its sedative and relaxant properties. (Full article...)
Fruit tree propagation is usually carried out vegetatively (non-sexually) by grafting or budding a desired variety onto a suitable rootstock.
Perennial plants can be propagated either by sexual or vegetative means. Sexual reproduction begins when a male germ cell (pollen) from one flower fertilises a female germ cell (ovule, incipient seed) of the same species, initiating the development of a fruit containing seeds. Each seed, when germinated, can grow to become a new specimen tree. However, the new tree inherits characteristics of both its parents, and it will not grow true to the variety of either parent from which it came. That is, it will be a fresh individual with an unpredictable combination of characteristics of its own. Although this is desirable in terms of producing novel combinations from the richness of the gene pool of the two parent plants (such sexual recombination is the source of new cultivars), only rarely will the resulting new fruit tree be directly useful or attractive to the tastes of humankind. Most new plants will have characteristics that lie somewhere between those of the two parents. (Full article...)
Image 11
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...)
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...)
Image 13
Soil scientists use the capital letters O, A, B, C, and E to identify the master horizons, and lowercase letters for distinctions of these horizons. Most soils have three major horizons—the surface horizon (A), the subsoil (B), and the substratum (C). Some soils have an organic horizon (O) on the surface, but this horizon can also be buried. The master horizon, E, is used for subsurface horizons that have a significant loss of minerals (eluviation). Hard bedrock, which is not soil, uses the letter R. Soil fertility refers to the ability of soil to sustain agricultural plant growth, i.e. to provide plant habitat and result in sustained and consistent yields of high quality. It also refers to the soil's ability to supply plant/crop nutrients in the right quantities and qualities over a sustained period of time. A fertile soil has the following properties:
The ability to supply essential plant nutrients and water in adequate amounts and proportions for plant growth and reproduction; and
The absence of toxic substances which may inhibit plant growth e.g. Fe2+ which leads to nutrient toxicity.
The following properties contribute to soil fertility in most situations:
Sufficient soil depth for adequate root growth and water retention;
Good internal drainage, allowing sufficient aeration for optimal root growth (although some plants, such as rice, tolerate waterlogging);
Vavilov's work was criticized by Trofim Lysenko, whose anti-Mendelian concepts of plant biology had won favor with Joseph Stalin. As a result, Vavilov was arrested and subsequently sentenced to death in July 1941. Although his sentence was commuted to twenty years' imprisonment, he died in prison in 1943. In 1955, his death sentence was retroactively pardoned under Nikita Khrushchev. By the late 1950s, his reputation was publicly rehabilitated, and he began to be hailed as a hero of Soviet science. (Full article...)
Image 15
Only a few of the many varieties of potato are commercially grown; others are heirlooms. An heirloom plant, heirloom variety, heritage fruit (Australia and New Zealand), or heirloom vegetable (especially in Ireland and the UK) is an old cultivar of a plant used for food that is grown and maintained by gardeners and farmers, particularly in isolated communities of the Western world. These were commonly grown during earlier periods in human history, but are not used in modern large-scale agriculture.
In some parts of the world, it is illegal to sell seeds of cultivars that are not listed as approved for sale. The Henry Doubleday Research Association, now known as Garden Organic, responded to this legislation by setting up the Heritage Seed Library to preserve seeds of as many of the older cultivars as possible. However, seed banks alone have not been able to provide sufficient insurance against catastrophic loss. In some jurisdictions, like Colombia, laws have been proposed that would make seed saving itself illegal. (Full article...)
Asclepias incarnata is a herbaceous, perennial plant species native to North America. It is found growing in damp to wet soils and also is cultivated as a garden plant for its attractive flowers. Its sap contains toxic chemicals.
Hippeastrum (/ˌhɪpiːˈæstrəm/) is a genus of about 90 species, and over 600 hybrids and cultivars, of perennial, herbaceous and bulbous plants, native to tropical and subtropical regions of the Americas, from Mexico south to Argentina and on some islands in the Caribbean. The majority have large, fleshy bulbs—usually about the size of a softball—and tall, broad, strap-like leaves that are (generally) evergreen, and large red or purple flowers. Numerous colors and cultivars have been created over the past hundred years.
Hippeastrum is a genus in the familyAmaryllidaceae (subfamilyAmaryllidoideae, tribeHippeastreae, and subtribeHippeastrinae). For many years, there has been confusion among botanists, as well as collectors and the general public, over the generic names Amaryllis and Hippeastrum; the former is a South African genus of plants, while the latter is a new world genus. However, the common name "amaryllis" has been used for Hippeastrum for years, especially for the ornamental cultivars (sold as indoor flowering bulbs around November and December, for Christmas, in the Northern Hemisphere). Within the genus Hippeastrum exist many epiphytic species, as well, which may be found living in natural debris and leaf litter on the crooks of tree branches; by comparison, Amaryllis is a primarily terrestrial, southern African genus of perennial bulbs. (Full article...)
Image 3
Mackenzie in 1944
Elke Mackenzie (11 September 1911 – 18 January 1990), born Ivan Mackenzie Lamb, was a British polar explorer and botanist who specialized in the field of lichenology. Beginning her education in Edinburgh, Scotland, Mackenzie later pursued botany at Edinburgh University, earning a Bachelor of Science degree in 1933 and a Doctor of Science in 1942. In the two years she was involved in Operation Tabarin, a covert World War II mission to Antarctica, she identified and documented many lichen species, several of them previously unknown to science.
Roystonea regia, commonly known as the royal palm, Cuban royal palm, or Florida royal palm, is a species of palm native to Mexico, the Caribbean, Florida, and parts of Central America. A large and attractive palm, it has been planted throughout the tropics and subtropics as an ornamental tree. Although it is sometimes called R. elata, the conserved nameR. regia is now the correct name for the species. The royal palm reaches heights from 15–24 m (50–80 ft) tall. Populations in Cuba and Florida were long seen as separate species, but are now considered a single species.
Widely planted as an ornamental, R. regia is also used for thatch, construction timber, and in some forms of traditional medicine, although there is currently no valid scientific evidence to support the efficacy or use of any palm species for medicinal purposes. The fruit is eaten by birds and bats (which disperse the seeds) and fed to livestock. Its flowers are visited by birds and bats, and it serves as a roosting site and food source for a variety of animals. Roystonea regia is the national tree of Cuba, and has a religious role both in Santería and Christianity, where it is used in Palm Sunday observances. (Full article...)
Image 5
Betula pubescens (syn. Betula alba), commonly known as downy birch and also as moor birch, white birch, European white birch or hairy birch, is a species of deciduous tree, native and abundant throughout northern Europe and northern Asia, growing farther north than any other broadleaf tree. It is closely related to, and often confused with, the silver birch (B. pendula), but grows in wetter places with heavier soils and poorer drainage; smaller trees can also be confused with the dwarf birch (B. nana).
Six varieties are recognised and it hybridises with the silver and dwarf birches. A number of cultivars have been developed but many are no longer in cultivation. The larva of the autumnal moth (Epirrita autumnata) feeds on the foliage and in some years, large areas of birch forest can be defoliated by this insect. Many fungi are associated with the tree and certain pathogenic fungi are the causal agents of birch dieback disease. (Full article...)
M. spinosissima thrive in well-drained soils that are sandy or loam, with a pH ranging from acidic to neutral. They prefer low humidity and full, filtered sun. Plants are typically watered once every two or three weeks, and kept nearly dry during the winter months. They require no pruning and make good patio and container plants. They are relatively disease resistant, but susceptible to pests such as mealybugs. Synonyms of M. spinosissima include Mammillaria centraliplumosa, Mammillaria haasii, and Mammillaria virginis. (Full article...)
Image 7
Rhinanthus minor, known as yellow rattle, is a herbaceous wildflower in the genus Rhinanthus in the familyOrobanchaceae (the broomrapes). It has circumpolar distribution in Europe, Russia, western Asia, and northern North America. An annual plant, yellow rattle grows up to 10–50 centimetres (3.9–19.7 in) tall, with upright stems and opposite, simple leaves. The fruit is a dry capsule, with loose, rattling seeds.
The preferred habitat of Rhinanthus minor is dry fields or meadows; it tolerates a wide range of soil types. It flowers in the summer between May and September. It is hemiparasitic, notably on Poaceae (grasses) and Fabaceae (legumes), and farmers consider it to be a pest, as it reduces grass growth. (Full article...)
In Slavic folklore, the raskovnik or razkovniche (SerbianCyrillic and Macedonian: расковник; Bulgarian: разковниче[rɐsˈkɔvnit͡ʃɛ]; Russian: разрыв-трава; Polish: rozryw) is a magical herb. According to lore, the raskovnik has the magical property to unlock or uncover anything that is locked or closed. However, legends claim it is notoriously difficult to recognize the herb, and reputedly only certain chthonic animals are able to identify it. (Full article...)
Image 9
Hypericum foliosum, the shining St John's wort, is a species of flowering plant in the family Hypericaceae. It is a bushy shrub endemic to the Portuguese Azores Islands with golden yellow petals and many stems. The species was described by William Aiton in 1789 and was later placed into section Androsaemum of the genus Hypericum by Norman Robson in 1984. It has a diverse essential oil profile made up mostly of monoterpene hydrocarbons, and significant concentrations of various medicinally useful phenols and carotenoids. Populations of the plant are small in number, but quick to colonize cleared areas like groves, landslide areas, and volcanic ash deposits. It is parasitized by fungus and by moth species, but is not considered endangered by the IUCN. H. foliosum is used in traditional medicine on the Azores for diuretic, hepatoprotective, and antihypertensive purposes. It also has in vitroantibiotic and antioxidizing capabilities. (Full article...)
Image 10
Richard Buxton aged 65, daguerreotype by John Benjamin Dancer Richard Buxton (15 January 1785 – 2 January 1865) was a British shoemaker and amateur botanist. Born in Prestwich, Lancashire, to a family who lived in humble circumstances, he taught himself to read, and learned the basic principles of botany. Although living as a pauper for most of his life, in 1849 he published A Botanical Guide to the Flowering Plants, Ferns, Mosses and Algæ, Found Indigenous Within Sixteen Miles of Manchester, which became one of the standard texts on the flora then commonly found in the Manchester area. According to his obituary in the Journal of Botany, British and Foreign, Buxton was one of "nature's gentlemen" and "his true and correct pronunciation of scientific terms have caused many who heard him to believe he was an accomplished classical scholar". He was acknowledged by the geologist Edward William Binney as "the most profound thinker of his class". (Full article...)
Image 11
Cultivar belonging to the Schlumbergera Truncata Group
Schlumbergera is a small genus of cacti with six to nine species found in the coastal mountains of south-eastern Brazil. These plants grow on trees or rocks in habitats that are generally shady with high humidity, and can be quite different in appearance from their desert-dwelling cousins. Most species of Schlumbergera have stems which resemble leaf-like pads joined one to the other and flowers which appear from areoles at the joints and tips of the stems. Two species have cylindrical stems more similar to other cacti.
Common names for these cacti generally refer to their flowering season. In the Northern Hemisphere, they are called Christmas cactus, Thanksgiving cactus, crab cactus and holiday cactus. In Brazil, the genus is referred to as Flor de Maio (May flower), reflecting the period in which they flower in the Southern Hemisphere. Most of the popular houseplants are cultivars of Schlumbergera, rather than species, with flowers in white, pink, yellow, orange, red or purple. The Easter cactus or Whitsun cactus, placed in the genus Rhipsalidopsis, is also called a holiday cactus and has flowers in red, orange, pink and white. (Full article...)
Image 12
White trillium blooming in Backus Woods (Ontario, Canada).
Trillium grandiflorum is most common in rich, mixed upland forests. It is easily recognised by its attractive three-petaled white flowers, opening from late spring to early summer, that rise above a whorl of three leaf-like bracts. It is an example of a spring ephemeral, a plant whose life-cycle is synchronised with that of the deciduous woodland which it favours. (Full article...)
Apples grown from seed tend to be very different from those of their parents, and the resultant fruit frequently lacks desired characteristics. For commercial purposes, including botanical evaluation, apple cultivars are propagated by clonal grafting onto rootstocks. Apple trees grown without rootstocks tend to be larger and much slower to fruit after planting. Rootstocks are used to control the speed of growth and the size of the resulting tree, allowing for easier harvesting. (Full article...)
Image 14
Spear Thistle The flora of Scotland is an assemblage of native plant species including over 1,600 vascular plants, more than 1,500 lichens and nearly 1,000 bryophytes. The total number of vascular species is low by world standards but lichens and bryophytes are abundant and the latter form a population of global importance. Various populations of rare fern exist, although the impact of 19th-century collectors threatened the existence of several species. The flora is generally typical of the north-west European part of the Palearctic realm and prominent features of the Scottish flora include borealCaledonian forest (much reduced from its natural extent), heather moorland and coastal machair. In addition to the native species of vascular plants there are numerous non-native introductions, now believed to make up some 43% of the species in the country.
There are a variety of important trees species and specimens; a Grand Fir in Argyll is the tallest tree in the United Kingdom and the Fortingall Yew may be the oldest tree in Europe. The Arran Whitebeams, Shetland Mouse-ear and Scottish Primrose are endemic flowering plants and there are a variety of endemic mosses and lichens. Conservation of the natural environment is well developed and various organisations play an important role in the stewardship of the country's flora. Numerous references to the country's flora appear in folklore, song and poetry. (Full article...)
Image 15
c. 1680Portrait of a Mathematician by Mary Beale, conjectured to be of Hooke but also conjectured to be of Isaac Barrow
Robert HookeFRS (/hʊk/; 18 July 1635 – 3 March 1703) was an English polymath who was active as a physicist ("natural philosopher"), astronomer, geologist, meteorologist and architect. He is credited as one of the first scientists to investigate living things at microscopic scale in 1665, using a compound microscope that he designed. Hooke was an impoverished scientific inquirer in young adulthood who went on to became one of the most important scientists of his time. After the Great Fire of London in 1666, Hooke (as a surveyor and architect) attained wealth and esteem by performing more than half of the property line surveys and assisting with the city's rapid reconstruction. Often vilified by writers in the centuries after his death, his reputation was restored at the end of the twentieth century and he has been called "England's Leonardo [da Vinci]".
Hooke was a Fellow of the Royal Society and from 1662, he was its first Curator of Experiments. From 1665 to 1703, he was also Professor of Geometry at Gresham College. Hooke began his scientific career as an assistant to the physical scientist Robert Boyle. Hooke built the vacuum pumps that were used in Boyle's experiments on gas law and also conducted experiments. In 1664, Hooke identified the rotations of Mars and Jupiter. Hooke's 1665 book Micrographia, in which he coined the term cell, encouraged microscopic investigations. Investigating optics – specifically light refraction – Hooke inferred a wave theory of light. His is the first-recorded hypothesis of the cause of the expansion of matter by heat, of air's composition by small particles in constant motion that thus generate its pressure, and of heat as energy. (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 plant biology professor Luca Comai independently developed glyphosate-resistant plants while working at Calgene and published his research before Monsanto researchers were able to?
Image 51 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 8A 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 13Structure 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 20Leaf lamina. The megaphyllous leaf architecture arose multiple times in different plant lineages (from Evolutionary history of plants)
Image 21The 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 22Micropropagation of transgenic plants (from Botany)
Image 23The 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 26Echeveria glauca in a Connecticut greenhouse. Botany uses Latin names for identification; here, the specific name glauca means blue. (from Botany)
Image 28This is an electron micrograph of the epidermal cells of a Brassica chinensis leaf. The stomates are also visible. (from Plant cell)
Image 29Five of the key areas of study within plant physiology (from Botany)
Image 30A 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 32The 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 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)