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
Wikispecies is a wiki-based online project supported by the Wikimedia Foundation. Its aim is to create a comprehensive free content catalogue of all species. Jimmy Wales stated that editors are not required to fax in their degrees, but that submissions will have to pass muster with a technical audience. Wikispecies is available under the GNU Free Documentation License and CC BY-SA 3.0. Started in September 2004, with biologists across the world invited to contribute, the project had grown a framework encompassing the Linnaean taxonomy with links to Wikipedia articles on individual species by April 2005. Benedikt Mandl co-ordinated the efforts of several people who are interested in getting involved with the project and contacted potential supporters in early summer 2004. Databases were evaluated and the administrators contacted, some of them have agreed on providing their data for Wikispecies. Mandl defined two major tasks: Figure out how the contents of the data base would need to be presented—by asking experts, potential non-professional users and comparing that with existing databases Figure out how to do the software, which hardware is required and how to cover the costs—by asking experts, looking for fellow volunteers and potential sponsorsAdvantages and disadvantages were discussed by the wikimedia-I mailing list.
The board of directors of the Wikimedia Foundation voted by 4 to 0 in favor of the establishment of a Wikispecies. The project is hosted at species.wikimedia.org. It was merged to a sister project of Wikimedia Foundation on September 14, 2004. On October 10, 2006, the project exceeded 75,000 articles. On May 20, 2007, the project exceeded 100,000 articles with a total of 5,495 registered users. On September 8, 2008, the project exceeded 150,000 articles with a total of 9,224 registered users. On October 23, 2011, the project reached 300,000 articles. On June 16, 2014, the project reached 400,000 articles. On January 7, 2017, the project reached 500,000 articles. On October 30, 2018, the project reached 600,000 articles, a total of 1.12 million pages. Wikispecies comprises taxon pages, additionally pages about synonyms, taxon authorities, taxonomical publications, institutions or repositories holding type specimen. Wikispecies asks users to use images from Wikimedia Commons. Wikispecies does not allow the use of content.
All Species Foundation Catalogue of Life Encyclopedia of Life Tree of Life Web Project List of online encyclopedias The Plant List Wikispecies, The free species directory that anyone can edit Species Community Portal The Wikispecies Charter, written by Wales
In plant systematics Epidendroideae is a subfamily of the orchid family, Orchidaceae. Epidendroideae is larger than all the other orchid subfamilies together, comprising more than 15,000 species in 576 genera. Most Epidendroid orchids are tropical epiphytes with pseudobulbs. There are, some terrestrials such as Epipactis and a few myco-heterotrophs, which are parasitic upon mycorrhizal fungi, they contain the remaining orchids with a single, fertile anther, fully incumbent to suberect. The anther form arises from early anther bending; the incumbent anther is pointed backward in many genera. Most have hard pollinia, i.e. a mass of waxy pollen or of coherent pollen grains. The pollinia are without; the stigma are three-lobed. The apical part of the middle stigma lobe forms a stipe; the ovary is unilocular. The leaves are distichous or spiraling; the Epidendroideae are difficult to classify. They have been divided in “lower epidendroids” and “higher epidendroids”. Epiphytes are plants which grow on top of other plants.
They are not parasitic. By growing on other plants, the epiphytes can reach to the light better or where they can avoid struggling for light. Many mosses and lichens are epiphytes, as are 10 per cent of all seed plants and ferns. Epiphytes are common in some groups of plants, such as ferns, mosses and algae. Over half of the 20,000 species of orchids are epiphytes. Most epiphytic seed plants and ferns are found in tropical and subtropical rainforests because they need high humidity to survive; the areas which most epiphytes grow are the montane rainforests. Epiphytic orchids are found on many positions of the host tree, depending on species requirements and size, some large species will grow in a fork, whereas some small species scramble through thin branches, other species will climb up the trunk etc. etc. The trees provide many habitats with different conditions of temperature and light. In temperate places, epiphytes are most common in moist forests, such as the rainforests in Queensland. Epiphytes are not adapted to droughts in the same way are other flora, because they don’t have access to the ground, but they still have some mechanisms to help them survive.
Some become dormant for months at a time. They contain absorptive plants that are capable at taking up water when it is available and preventing drought when water is scarcer. CAM can be impeded by higher night-time temperatures, dehydrated tissues, high saturation deficits in the surrounding air, which lower the "stomata conductance" of the epiphytes, reducing the CO2 uptake, which in turn reduces growth and reproduction and induces carbon loss. Higher temperatures, strain on evaporation, contact to light cause CAM-idling, the epiphyte closing its stomata when it becomes stressed, that brings down the range of habitats a species can inhabit. Epiphyte species work biomasses are much more sensitive to different relative moisture levels than other plants; the Epidendroideae subfamily is divided into two clades or subgroups known as the higher epidendroids and the lower epidendroids. The higher epidendroids are monophyletic and polyphyletic; the tribes are listed below: This classification has a rather ephemeral nature and is prone to frequent revision.
Changes are to occur as new morphological and genetic data become available. A phylogenetic analysis of the Orchidaceae - evidence from rbcL nucleotide sequences Orchid Tree: a phylogeny of epiphytes on the tree of life
In botany and dendrology, a rhizome is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are called creeping rootstalks or just rootstalks. Rhizomes grow horizontally; the rhizome retains the ability to allow new shoots to grow upwards. A rhizome is the main stem of the plant. A stolon is similar to a rhizome, but a stolon sprouts from an existing stem, has long internodes, generates new shoots at the end, such as in the strawberry plant. In general, rhizomes have short internodes, send out roots from the bottom of the nodes, generate new upward-growing shoots from the top of the nodes. A stem tuber is a thickened part of a rhizome or stolon, enlarged for use as a storage organ. In general, a tuber is high in starch, e.g. the potato, a modified stolon. The term "tuber" is used imprecisely and is sometimes applied to plants with rhizomes. If a rhizome is separated each piece may be able to give rise to a new plant; the plant uses the rhizome to store starches and other nutrients.
These nutrients become useful for the plant when new shoots must be formed or when the plant dies back for the winter. This is a process known as vegetative reproduction and is used by farmers and gardeners to propagate certain plants; this allows for lateral spread of grasses like bamboo and bunch grasses. Examples of plants that are propagated this way include hops, ginger, lily of the valley and sympodial orchids; some rhizomes which are used directly in cooking include ginger, galangal and lotus. Stored rhizomes are subject to bacterial and fungal infections, making them unsuitable for replanting and diminishing stocks. However, rhizomes can be produced artificially from tissue cultures; the ability to grow rhizomes from tissue cultures leads to better stocks for replanting and greater yields. The plant hormones ethylene and jasmonic acid have been found to help induce and regulate the growth of rhizomes in rhubarb. Ethylene, applied externally was found to affect internal ethylene levels, allowing easy manipulations of ethylene concentrations.
Knowledge of how to use these hormones to induce rhizome growth could help farmers and biologists producing plants grown from rhizomes more cultivate and grow better plants. Some plants have rhizomes that grow above ground or that lie at the soil surface, including some Iris species, ferns, whose spreading stems are rhizomes. Plants with underground rhizomes include gingers, the Venus flytrap, Chinese lantern, western poison-oak and Alstroemeria, the weeds Johnson grass, Bermuda grass, purple nut sedge. Rhizomes form a single layer, but in giant horsetails, can be multi-tiered. Many rhizomes have culinary value, some, such as zhe'ergen, are consumed raw. Aspen Corm Mycorrhiza Media related to Rhizomes at Wikimedia Commons The Rhizome Collective for sustainable living
The pseudobulb is a storage organ found in many epiphytic and terrestrial sympodial orchids. It is derived from a thickening of the part of a stem between leaf nodes and may be composed of just one internode or several, termed heteroblastic and homoblastic respectively. All leaves and inflorescences arise from this structure. Pseudobulbs formed from a single internode produce the leaves and inflorescence from the top, while those that are formed from several internodes can possess leaves along its length; the modified sheath leaves that appear at the base of a pseudobulb and enfold all or part of it are dry and papery, though in some orchids the sheaths bear leaf blades and the leaves at the pseudobulb's apex are reduced to scales. In some species, it is hardly swollen at all and looks like a normal stem with many leaves while at the other extreme, some genera such as Bulbophyllum have single, spherical pseudobulbs with one leaves at the apex of each. Whether cane-like or spherical, they are all produced from a long-lived creeping stem called a rhizome which may itself be climbing or pendulous.
The pseudobulbs are short lived, but are continually produced from the growing tip of the rhizome and may persist for years after its last leaves senesce. The term pseudobulb is used to distinguish the above-ground storage organ from other storage organs derived from stems that were underground, namely corms or true bulbs, a combination of an underground stem and storage leaves. Speaking, there is no clear distinction between the pseudobulb and corm structures. Media related to Pseudobulb at Wikimedia Commons
The flowering plants known as angiosperms, Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 64 orders, 416 families 13,164 known genera and c. 369,000 known species. Like gymnosperms, angiosperms are seed-producing plants. However, they are distinguished from gymnosperms by characteristics including flowers, endosperm within the seeds, the production of fruits that contain the seeds. Etymologically, angiosperm means a plant; the term comes from the Greek words sperma. The ancestors of flowering plants diverged from gymnosperms in the Triassic Period, 245 to 202 million years ago, the first flowering plants are known from 160 mya, they diversified extensively during the Early Cretaceous, became widespread by 120 mya, replaced conifers as the dominant trees from 100 to 60 mya. Angiosperms differ from other seed plants in several ways, described in the table below; these distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans.
Angiosperm stems are made up of seven layers. The amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms; the vascular bundles of the stem are arranged such that the phloem form concentric rings. In the dicotyledons, the bundles in the young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles, a complete ring is formed, a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside; the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.
Among the monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They once formed the stem increases in diameter only in exceptional cases; the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, provide the most trustworthy external characteristics for establishing relationships among angiosperm species; the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally from the axil of a leaf; as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. More the flower-bearing portion of the plant is distinguished from the foliage-bearing or vegetative portion, forms a more or less elaborate branch-system called an inflorescence. There are two kinds of reproductive cells produced by flowers. Microspores, which will divide to become pollen grains, are the "male" cells and are borne in the stamens.
The "female" cells called megaspores, which will divide to become the egg cell, are contained in the ovule and enclosed in the carpel. The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators; the individual members of these surrounding structures are known as petals. The outer series is green and leaf-like, functions to protect the rest of the flower the bud; the inner series is, in general, white or brightly colored, is more delicate in structure. It functions to attract bird pollinators. Attraction is effected by color and nectar, which may be secreted in some part of the flower; the characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans. While the majority of flowers are perfect or hermaphrodite, flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization.
Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot transfer pollen to the pistil. Homomorphic flowers may employ a biochemical mechanism called self-incompatibility to discriminate between self and non-self pollen grains. In other species, the male and female parts are morphologically separated, developing on different flowers; the botanical term "Angiosperm", from the Ancient Greek αγγείον, angeíon and σπέρμα, was coined in the form Angiospermae by Paul Hermann in 1690, as the name of one of his primary divisions of the plant kingdom. This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked; the term and its antonym were maintained by Carl Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Its use with any
Monocotyledons referred to as monocots, are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided, the rest of the flowering plants having two cotyledons and therefore classified as dicotyledons, or dicots. However, molecular phylogenetic research has shown that while the monocots form a monophyletic group or clade, the dicots do not. Monocots have always been recognized as a group, but with various taxonomic ranks and under several different names; the APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank. The monocots include about 60,000 species; the largest family in this group by number of species are the orchids, with more than 20,000 species. About half as many species belong to the true grasses, which are economically the most important family of monocots. In agriculture the majority of the biomass produced; these include not only major grains, but forage grasses, sugar cane, the bamboos.
Other economically important monocot crops include various palms and plantains, gingers and their relatives and cardamom, pineapple, water chestnut, leeks and garlic. Many houseplants are monocot epiphytes. Additionally most of the horticultural bulbs, plants cultivated for their blooms, such as lilies, irises, cannas and tulips, are monocots; the monocots or monocotyledons have, as the name implies, a single cotyledon, or embryonic leaf, in their seeds. This feature was used to contrast the monocots with the dicotyledons or dicots which have two cotyledons. From a diagnostic point of view the number of cotyledons is neither a useful characteristic, nor is it reliable; the single cotyledon is only one of a number of modifications of the body plan of the ancestral monocotyledons, whose adaptive advantages are poorly understood, but may have been related to adaption to aquatic habitats, prior to radiation to terrestrial habitats. Monocots are sufficiently distinctive that there has been disagreement as to membership of this group, despite considerable diversity in terms of external morphology.
However, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity. On the one hand the organisation of the shoots, leaf structure and floral configuration are more uniform than in the remaining angiosperms, yet within these constraints a wealth of diversity exists, indicating a high degree of evolutionary success. Monocot diversity includes perennial geophytes such as ornamental flowers including and succulent epiphytes, all in the lilioid monocots, major cereal grains in the grass family and forage grasses as well as woody tree-like palm trees, bamboo and bromeliads, bananas and ginger in the commelinid monocots, as well as both emergent and aroids, as well as floating or submerged aquatic plants such as seagrass. Organisation and life formsThe most important distinction is their growth pattern, lacking a lateral meristem that allows for continual growth in diameter with height, therefore this characteristic is a basic limitation in shoot construction.
Although herbaceous, some arboraceous monocots reach great height and mass. The latter include agaves, palms and bamboos; this creates challenges in water transport. Some, such as species of Yucca, develop anomalous secondary growth, while palm trees utilise an anomalous primary growth form described as establishment growth; the axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis. The limited conductivity contributes to limited branching of the stems. Despite these limitations a wide variety of adaptive growth forms has resulted from epiphytic orchids and bromeliads to submarine Alismatales and mycotrophic Burmanniaceae and Triuridaceae. Other forms of adaptation include the climbing vines of Araceae which use negative phototropism to locate host trees, while some palms such as Calamus manan produce the longest shoots in the plant kingdom, up to 185 m long. Other monocots Poales, have adopted a therophyte life form.
LeavesThe cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll and a distal hyperphyll. In monocots the hypophyll tends to be the dominant part in contrast to other angiosperms. From these, considerable diversity arises. Mature monocot leaves are narrow and linear, forming a sheath