An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, water or from debris accumulating around it. Epiphytes take part in nutrient cycles and add to both the diversity and biomass of the ecosystem in which they occur, like any other organism, they are an important source of food for many species. The older parts of a plant will have more epiphytes growing on them. Epiphytes differ from parasites in that epiphytes grow on other plants for physical support and do not negatively affect the host. An epiphytic organism, not a plant is sometimes called an epibiont. Epiphytes are found in the temperate zone or in the tropics. Epiphyte species make good houseplants due to their minimal soil requirements. Epiphytes provide a rich and diverse habitat for other organisms including animals, fungi and myxomycetes. Epiphyte is one of the subdivisions of the Raunkiær system; the term epiphytic derives from the Greek epi- and phyton. Epiphytic plants are sometimes called "air plants".
However, there are many aquatic species of algae. The best-known epiphytic plants include mosses and bromeliads such as Spanish moss, but epiphytes may be found in every major group of the plant kingdom. 89% of terrestrial epiphyte species are flowering plants. The second largest group are the leptosporangiate ferns, with about 2800 species. In fact, about one third of all ferns are epiphytes; the third largest group is clubmosses, with 190 species, followed by a handful of species in each of the spikemosses, other ferns and cycads. The first important monograph on epiphytic plant ecology was written by A. F. W. Schimper. Assemblages of large epiphytes occur most abundantly in moist tropical forests, but mosses and lichens occur as epiphytes in all biomes. In Europe there are no dedicated epiphytic plants using roots, but rich assemblages of mosses and lichens grow on trees in damp areas, the common polypody fern grows epiphytically along branches. Grass, small bushes or small trees may grow in suspended soils up trees.
Epiphytes however, can be categorized into holo-epiphytes or hemi-epiphytes. A holo-epiphyte is a plant that spends its whole life cycle without contact with the ground and a hemi-epiphyte is a plant that spends only half of its life without the ground before the roots can reach or make contact with the ground. Orchids are a common example of holo-epiphytes and Strangler Figs are an example of hemi-epiphytes. Epiphytes are not connected to the soil, must get nutrients from other sources, such as fog, dew and mist, or from nutrients being released from the ground rooted plants by decomposition or leaching, dinitrogen fixation. Epiphytic plants attached to their hosts high in the canopy have an advantage over herbs restricted to the ground where there is less light and herbivores may be more active. Epiphytic plants are important to certain animals that may live in their water reservoirs, such as some types of frogs and arthropods. Epiphytes can have a significant effect on the microenvironment of their host, of ecosystems where they are abundant, as they hold water in the canopy and decrease water input to the soil.
Some non-vascular epiphytes such as lichens and mosses are well known for their ability to take up water rapidly. The epiphytes create a cooler and moister environment in the host plant canopy greatly reducing water loss by the host through transpiration; the ecology of epiphytes in marine environments differs from those in terrestrial ecosystems. Epiphytes in marine systems are species of algae, fungi, bryozoans, protozoa, crustaceans and any other sessile organism that grows on the surface of a plant seagrasses or algae. Settlement of epiphytic species is influenced by a number of factors including light, currents and trophic interactions. Algae are the most common group of epiphytes in marine systems. Photosynthetic epiphytes account for a large amount of the photosynthesis in systems in which they occur; this is between 20 and 60% of the total primary production of the ecosystem. They are a general group of organisms and are diverse, providing food for a great number of fauna. Snail and nudibranch species are two common grazers of epiphytes.
Epiphyte species composition and the amount of epiphytes can be indicative of changes in the environment. Recent increases in epiphyte abundance have been linked to excessive nitrogen put into the environment from farm runoff and storm water. High abundance of epiphytes are considered detrimental to the plants that they grow on causing damage or death in seagrasses; this is. Epiphytes in marine systems are known to grow with fast generation times. Epiphyllum - a genus of epiphytic cacti Parasitic plant Epilith, an organism that grows in a rock Epibiont, an organism that grows on another life form Epiphytic bacteria Epiphytic fungus Epiphytes on a Scot's Pine in Gorbie Glen, Scotland
Antoine Laurent de Jussieu
Antoine Laurent de Jussieu was a French botanist, notable as the first to publish a natural classification of flowering plants. His classification was based on an extended unpublished work by his uncle, the botanist Bernard de Jussieu. Jussieu was born in Lyon, he went to Paris to study medicine, graduating in 1770. He was professor of botany at the Jardin des Plantes from 1770 to 1826, his son Adrien-Henri became a botanist. In his study of flowering plants, Genera plantarum, Jussieu adopted a methodology based on the use of multiple characters to define groups, an idea derived from naturalist Michel Adanson; this was a significant improvement over the "artificial" system of Linnaeus, whose most popular work classified plants into classes and orders based on the number of stamens and pistils. Jussieu did keep Linnaeus' binomial nomenclature, resulting in a work, far-reaching in its impact. Morton's 1981 History of botanical science counts 76 of Jussieu's families conserved in the ICBN, versus just 11 for Linnaeus, for instance.
Writing of the natural system, Sydney Howard Vines remarked "The glory of this crowning achievement belongs to Jussieu: he was the capable man who appeared at the psychological moment, it is the men that so appear who have made, will continue to make, all the great generalisations of science." In 1788, he was elected a foreign member of the Royal Swedish Academy of Sciences. He was a member of Les Neuf Sœurs; the system of suprageneric nomenclature in botany is dated to 4 Aug 1789 with the publication of the Genera Plantarum. De Jussieu system
Carl Linnaeus known after his ennoblement as Carl von Linné, was a Swedish botanist and zoologist who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin, his name is rendered in Latin as Carolus Linnæus. Linnaeus was born in the countryside of Småland in southern Sweden, he received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and published the first edition of his Systema Naturae in the Netherlands, he returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he continued to collect and classify animals and minerals, while publishing several volumes, he was one of the most acclaimed scientists in Europe at the time of his death. Philosopher Jean-Jacques Rousseau sent him the message: "Tell him I know no greater man on earth."
Johann Wolfgang von Goethe wrote: "With the exception of Shakespeare and Spinoza, I know no one among the no longer living who has influenced me more strongly." Swedish author August Strindberg wrote: "Linnaeus was in reality a poet who happened to become a naturalist." Linnaeus has been called Princeps botanicorum and "The Pliny of the North". He is considered as one of the founders of modern ecology. In botany and zoology, the abbreviation L. is used to indicate Linnaeus as the authority for a species' name. In older publications, the abbreviation "Linn." is found. Linnaeus's remains comprise the type specimen for the species Homo sapiens following the International Code of Zoological Nomenclature, since the sole specimen that he is known to have examined was himself. Linnaeus was born in the village of Råshult in Småland, Sweden, on 23 May 1707, he was the first child of Christina Brodersonia. His siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, Emerentia Linnæa, his father taught him Latin as a small child.
One of a long line of peasants and priests, Nils was an amateur botanist, a Lutheran minister, the curate of the small village of Stenbrohult in Småland. Christina was the daughter of the rector of Samuel Brodersonius. A year after Linnaeus's birth, his grandfather Samuel Brodersonius died, his father Nils became the rector of Stenbrohult; the family moved into the rectory from the curate's house. In his early years, Linnaeus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and showed flowers to Linnaeus and told him their names. Soon Linnaeus was given his own patch of earth. Carl's father was the first in his ancestry to adopt a permanent surname. Before that, ancestors had used the patronymic naming system of Scandinavian countries: his father was named Ingemarsson after his father Ingemar Bengtsson; when Nils was admitted to the University of Lund, he had to take on a family name. He adopted the Latinate name Linnæus after a giant linden tree, lind in Swedish, that grew on the family homestead.
This name was spelled with the æ ligature. When Carl was born, he was named Carl Linnæus, with his father's family name; the son always spelled it with the æ ligature, both in handwritten documents and in publications. Carl's patronymic would have been Nilsson, as in Carl Nilsson Linnæus. Linnaeus's father began teaching him basic Latin and geography at an early age; when Linnaeus was seven, Nils decided to hire a tutor for him. The parents picked a son of a local yeoman. Linnaeus did not like him, writing in his autobiography that Telander "was better calculated to extinguish a child's talents than develop them". Two years after his tutoring had begun, he was sent to the Lower Grammar School at Växjö in 1717. Linnaeus studied going to the countryside to look for plants, he reached the last year of the Lower School when he was fifteen, taught by the headmaster, Daniel Lannerus, interested in botany. Lannerus gave him the run of his garden, he introduced him to Johan Rothman, the state doctor of Småland and a teacher at Katedralskolan in Växjö.
A botanist, Rothman broadened Linnaeus's interest in botany and helped him develop an interest in medicine. By the age of 17, Linnaeus had become well acquainted with the existing botanical literature, he remarks in his journal that he "read day and night, knowing like the back of my hand, Arvidh Månsson's Rydaholm Book of Herbs, Tillandz's Flora Åboensis, Palmberg's Serta Florea Suecana, Bromelii Chloros Gothica and Rudbeckii Hortus Upsaliensis...."Linnaeus entered the Växjö Katedralskola in 1724, where he studied Greek, Hebrew and mathematics, a curriculum designed for boys preparing for the priesthood. In the last year at the gymnasium, Linnaeus's father visited to ask the professors how his son's studies were progressing. Rothman believed otherwise; the doctor offered to have Linnaeus live with his family in Växjö and to teach him physiology and botany. Nils accepted this offer. Rothman showed Linnaeus that botany was a serious sub
Cuscuta (Chinese: 菟絲子） is a genus of about 100–170 species of yellow, orange, or red parasitic plants. Treated as the only genus in the family Cuscutaceae, it now is accepted as belonging in the morning glory family, Convolvulaceae, on the basis of the work of the Angiosperm Phylogeny Group; the genus is found throughout the temperate and tropical regions of the world, with the greatest species diversity in subtropical and tropical regions. Folk names include: strangle tare, beggarweed, lady's laces, wizard's net, devil's guts, devil's hair, devil's ringlet, hailweed, hellbine, love vine, pull-down, angel hair, witch's hair. Dodder can be identified by its thin stems appearing leafless, with the leaves reduced to minute scales. In these respects it resembles the parasitic, but unrelated genus Cassytha. From mid-summer to early autumn, the vines can produce small fruit that take the same color as the vine, are the size of a common pea, it has low levels of chlorophyll. Dodder flowers range in color from white to pink to yellow to cream.
Some flower in the early summer, others depending on the species. The seeds are minute and produced in large quantities, they have a hard coating, can survive in the soil for 5–10 years, sometimes longer. Dodder seeds sprout near the surface of the soil. Although dodder germination can occur without a host, it has to reach a green plant and is adapted to grow towards the nearby plants by following chemosensory clues. If a plant is not reached within 5 to 10 days of germination, the dodder seedling will die. Before a host plant is reached, the dodder, as other plants, relies on food reserves in the embryo. After a dodder attaches itself to a plant, it wraps itself around it. If the host contains food beneficial to dodder, the dodder produces haustoria that insert themselves into the vascular system of the host; the original root of the dodder in the soil dies. The dodder can attach itself to multiple plants. In tropical areas it can grow more or less continuously, may reach high into the canopy of shrubs and trees.
Dodder is parasitic on a wide variety of plants, including a number of agricultural and horticultural crop species, such as alfalfa, flax, potatoes, dahlia, trumpet vine and petunias, more. It is an ectoparasite. Dodder ranges in severity based on its species and the species of the host, the time of attack, whether any viruses are present in the host plant. By debilitating the host plant, dodder decreases the ability of plants to resist viral diseases, dodder can spread plant diseases from one host to another if it is attached to more than one plant; this is of economic concern in agricultural systems, where an annual drop of 10% yield can be devastating. There has been an emphasis on dodder vine control. A report published in Science in 2006 demonstrated that dodder use airborne volatile organic compound cues to locate their host plants. Seedlings of Cuscuta pentagona exhibit positive growth responses to volatiles released by tomato and other species of host plants; when given a choice between volatiles released by the preferred host tomato and the non-host wheat, the parasite grew toward the former.
Further experiments demonstrated attraction to a number of individual compounds released by host plants and repellance by one compound released by wheat. These results do not rule out the possibility that other cues, such as light, may play a role in host location. Less is known about host defenses against dodder and other parasitic plants than is known about plant defenses against herbivores and pathogens. In one study, tomato plants were found to employ complex mechanisms to defend against dodder. Two pathways, using jasmonic acid and salicylic acid, were activated in response to attack by Cuscuta pentagona. Dodder attack was found to induce production of volatiles, including 2-carene, α-pinene, β-phellandrene, it is not known if or how these volatiles defend the host, but they could interfere with the dodder's ability to locate and select hosts. The presence of trichomes on the tomato stem blocks the dodder from attaching to the stem. Many countries have laws prohibiting import of dodder seed, requiring crop seeds to be free of dodder seed contamination.
Before planting, all clothes should be inspected for dodder seed when moving from an infested area to a non-infested crop. When dealing with an infested area, swift action is necessary. Recommendations include planting a non-host crop for several years after the infestation, pulling up host crops particularly before the dodder produces seed, use of preemergent herbicides such as Dacthal in the spring. Examples of non-host crops include many other monocotyledons. If dodder is found before it chokes a host plant, it may be removed from the soil. If choking has begun, the host plant must be pruned below the dodder infestation, as dodder is versatile and able to grow back from its haustoria. C. chinensis seeds have long been used for osteoporosis in some other Asian countries. C. chinensis is a comm
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. In wider definitions, the taller palms, tree ferns and bamboos are trees. Trees have been in existence for 370 million years, it is estimated. A tree has many secondary branches supported clear of the ground by the trunk; this trunk contains woody tissue for strength, vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark. Below the ground, the roots spread out widely. Above ground, the branches divide into smaller shoots.
The shoots bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development. Trees reproduce using seeds. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones. Palms and bamboos produce seeds, but tree ferns produce spores instead. Trees play a significant role in moderating the climate, they remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, fruit for food as well as having many other uses. In parts of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture; because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, they play a role in many of the world's mythologies.
Although "tree" is a term of common parlance, there is no universally recognised precise definition of what a tree is, either botanically or in common language. In its broadest sense, a tree is any plant with the general form of an elongated stem, or trunk, which supports the photosynthetic leaves or branches at some distance above the ground. Trees are typically defined by height, with smaller plants from 0.5 to 10 m being called shrubs, so the minimum height of a tree is only loosely defined. Large herbaceous plants such as papaya and bananas are trees in this broad sense. A applied narrower definition is that a tree has a woody trunk formed by secondary growth, meaning that the trunk thickens each year by growing outwards, in addition to the primary upwards growth from the growing tip. Under such a definition, herbaceous plants such as palms and papayas are not considered trees regardless of their height, growth form or stem girth. Certain monocots may be considered trees under a looser definition.
Aside from structural definitions, trees are defined by use. The tree growth habit is an evolutionary adaptation found in different groups of plants: by growing taller, trees are able to compete better for sunlight. Trees tend some reaching several thousand years old. Several trees are among the oldest organisms now living. Trees have modified structures such as thicker stems composed of specialised cells that add structural strength and durability, allowing them to grow taller than many other plants and to spread out their foliage, they differ from shrubs, which have a similar growth form, by growing larger and having a single main stem. The tree form has evolved separately in unrelated classes of plants in response to similar environmental challenges, making it a classic example of parallel evolution. With an estimated 60,000-100,000 species, the number of trees worldwide might total twenty-five per cent of all living plant species; the greatest number of these grow in tropical regions and many of these areas have not yet been surveyed by botanists, making tree diversity and ranges poorly known.
The majority of tree species are angiosperms. There are about 1000 species of gymnosperm trees, including conifers, cycads and gnetales. Most angiosperm trees are eudicots, the "true dicotyledons", so named because the seeds contain two cotyledons or seed leaves. There are some trees among the old lineages of flowering plants called basal angiosperms or paleodicots. Wood gives structural strength to the trunk of most types of tree; the vascular system of trees allows water and other chemicals to be di
In the APG IV system for the classification of flowering plants, the name asterids denotes a clade. Common examples include the forget-me-nots, the common sunflower, morning glory and sweet potato, lavender, olive, honeysuckle, ash tree, snapdragon, psyllium, garden sage, table herbs such as mint and rosemary, rainforest trees such as Brazil nut. Most of the taxa belonging to this clade had been referred to the Asteridae in the Cronquist system and to the Sympetalae in earlier systems; the name asterids resembles the earlier botanical name but is intended to be the name of a clade rather than a formal ranked name, in the sense of the ICBN. The phylogenetic tree presented hereafter has been proposed by the APG IV project. Genetic analysis carried out after APG II maintains that the sister to all other asterids are the Cornales. A second order that split from the base of the asterids are the Ericales; the remaining orders cluster into two clades, the lamiids and the campanulids. The structure of both of these clades has changed in APG III.
In APG III system, the following clades were renamed: euasterids I → lamiids euasterids II → campanulids Asterids in Stevens, P. F.. Angiosperm Phylogeny Website. Version 7, May 2006
The Solanales are an order of flowering plants, included in the asterid group of dicotyledons. Some older sources used the name Polemoniales for this order. Under the older Cronquist system, the latter three families were placed elsewhere, a number of others were included: Family Duckeodendraceae Family Nolanaceae Family Cuscutaceae Family Retziaceae Family Menyanthaceae Family Polemoniaceae Family Hydrophyllaceae In the classification system of Dahlgren the Solanales were in the superorder Solaniflorae; the following families are included here in newer systems such as that of the Angiosperm Phylogeny Group: Family Solanaceae Family Convolvulaceae Family Montiniaceae Family Sphenocleaceae Family HydroleaceaeThe APG II classification treats the Solanales in the group Euasterids I. "Solanales". Integrated Taxonomic Information System. Systema Naturae 2000 Media related to Solanales at Wikimedia Commons