91-439: Holcoglossum ( Holc. ) is a genus of orchids, in the family Orchidaceae . It is native from Assam through mainland China to Taiwan and Indo-China . All species of this genus are perennial epi- or lithophytes and are characterized by a short monopodial shoot axis with terete or cross-sectionally triangular leaves. The upper side forms a groove with the folded edges of the leaves. The leaves are tapered and not notched at
182-464: A carbohydrate energy source. The carbohydrate source can be combinations of discrete sugars or can be derived from other sources such as banana , pineapple , peach , or even tomato puree or coconut water . After the preparation of the agar medium, it is poured into test tubes or jars which are then autoclaved (or cooked in a pressure cooker) to sterilize the medium. After cooking, the medium begins to gel as it cools. The taxonomy of this family
273-450: A phylogenetic study showed strong statistical support for the following topology of the orchid tree , using 9 kb of plastid and nuclear DNA from 7 genes , a topology that was confirmed by a phylogenomic study in the same year. Apostasioideae Vanilloideae Habitat (ecology) In ecology , habitat refers to the array of resources, physical and biotic factors that are present in an area, such as to support
364-401: A seta , knocking the pollinator off the flower. After pollination, the sepals and petals fade and wilt, but they usually remain attached to the ovary. In 2011, Bulbophyllum nocturnum was discovered to flower nocturnally. Some species, such as in the genera Phalaenopsis , Dendrobium , and Vanda , produce offshoots or plantlets formed from one of the nodes along the stem , through
455-474: A spur of the labellum ( 8 in the illustration above), or on the point of the sepals, or in the septa of the ovary, the most typical position amongst the Asparagales . In orchids that produce pollinia, pollination happens as some variant of the following sequence: when the pollinator enters into the flower, it touches a viscidium, which promptly sticks to its body, generally on the head or abdomen. While leaving
546-551: A velamen , has the function of absorbing humidity. It is made of dead cells and can have a silvery-grey, white or brown appearance. In some orchids, the velamen includes spongy and fibrous bodies near the passage cells, called tilosomes. The cells of the root epidermis grow at a right angle to the axis of the root to allow them to get a firm grasp on their support. Nutrients for epiphytic orchids mainly come from mineral dust, organic detritus, animal droppings and other substances collecting among on their supporting surfaces. The base of
637-474: A basket without substrate. Any substrate used should be very coarse in texture to allow good air circulation at the roots. The plants need a very bright but also cool location. They should be watered regularly, with drier periods during dormancy. In the Meise Botanic Garden , Holcoglossum kimballianum are kept in an alpine greenhouse, where you have to condense your own breath and wear a parka. In nature,
728-647: A conduit for the dispersal of pollen grains, spores and seeds , the atmosphere can be considered to be a habitat-type in its own right. There are metabolically active microbes present that actively reproduce and spend their whole existence airborne, with hundreds of thousands of individual organisms estimated to be present in a cubic meter of air. The airborne microbial community may be as diverse as that found in soil or other terrestrial environments, however, these organisms are not evenly distributed, their densities varying spatially with altitude and environmental conditions. Aerobiology has not been studied much, but there
819-412: A cool to cold habitat. The small species from this genus can be cultivated in small pots or baskets or tied to cork plates. Native of cool, damp woods, they require low temperatures and a light spot. In full sun, however, there is a risk of heat build-up. The plants often need water during the growth phase, and less frequent watering during the resting phase without letting them dry out. For a pot culture,
910-473: A different species of bee, so as to enforce proper cross-pollination. A rare achlorophyllous saprophytic orchid growing entirely underground in Australia, Rhizanthella slateri , is never exposed to light, and depends on ants and other terrestrial insects to pollinate it. Catasetum , a genus discussed briefly by Darwin , actually launches its viscid pollinia with explosive force when an insect touches
1001-489: A downpour occurs and lays its eggs in the transient pools that form; the tadpoles develop with great rapidity, sometimes in as little as nine days, undergo metamorphosis , and feed voraciously before digging a burrow of their own. Other organisms cope with the drying up of their aqueous habitat in other ways. Vernal pools are ephemeral ponds that form in the rainy season and dry up afterwards. They have their specially-adapted characteristic flora, mainly consisting of annuals,
SECTION 10
#17328525455631092-413: A forest is divided into parts by logging, with strips of cleared land separating woodland blocks, and the distances between the remaining fragments exceeds the distance an individual animal is able to travel, that species becomes especially vulnerable. Small populations generally lack genetic diversity and may be threatened by increased predation, increased competition, disease and unexpected catastrophe. At
1183-526: A home for both static organisms, anchored to the substrate , and for a large range of organisms crawling on or burrowing into the surface. Some creatures float among the waves on the surface of the water, or raft on floating debris, others swim at a range of depths, including organisms in the demersal zone close to the seabed, and myriads of organisms drift with the currents and form the plankton . Many animals and plants have taken up residence in urban environments. They tend to be adaptable generalists and use
1274-709: A mile below the ice of Antarctica; in the absence of sunlight, they must rely on organic material from elsewhere, perhaps decaying matter from glacier melt water or minerals from the underlying rock. Other bacteria can be found in abundance in the Mariana Trench , the deepest place in the ocean and on Earth; marine snow drifts down from the surface layers of the sea and accumulates in this undersea valley, providing nourishment for an extensive community of bacteria. Other microbes live in environments lacking in oxygen, and are dependent on chemical reactions other than photosynthesis . Boreholes drilled 300 m (1,000 ft) into
1365-444: A natural habitat is no longer able to support its native species. The organisms once living there have either moved to elsewhere or are dead, leading to a decrease in biodiversity and species numbers . Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. The protection of habitat types is a necessary step in the maintenance of biodiversity because if habitat destruction occurs,
1456-410: A parasitic organism, its habitat is the particular part of the outside or inside of its host on or in which it is adapted to live. The life cycle of some parasites involves several different host species, as well as free-living life stages, sometimes within vastly different microhabitat types. One such organism is the trematode (flatworm) Microphallus turgidus , present in brackish water marshes in
1547-557: A particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities and its efficiency as a colonizer. Arid habitats are those where there is little available water. The most extreme arid habitats are deserts . Desert animals have a variety of adaptations to survive the dry conditions. Some frogs live in deserts, creating moist habitat types underground and hibernating while conditions are adverse. Couch's spadefoot toad ( Scaphiopus couchii ) emerges from its burrow when
1638-415: A rotten log, a rock or a clump of moss ; a parasitic organism has as its habitat the body of its host , part of the host's body (such as the digestive tract), or a single cell within the host's body. Habitat types are environmental categorizations of different environments based on the characteristics of a given geographical area, particularly vegetation and climate. Thus habitat types do not refer to
1729-455: A semiterrestrial or rock-hugging (" lithophyte ") orchid, show a sparkling silver and gold veining on a light green background. The cordate leaves of Psychopsiella limminghei are light brownish-green with maroon-puce markings, created by flower pigments. The attractive mottle of the leaves of lady's slippers from tropical and subtropical Asia ( Paphiopedilum ), is caused by uneven distribution of chlorophyll. Also, Phalaenopsis schilleriana
1820-487: A similar way; their eggs hatch and the juvenile fish grow with great rapidity when the conditions are right, but the whole population of fish may end up as eggs in diapause in the dried up mud that was once a pond. Freshwater habitat types include rivers, streams, lakes, ponds, marshes and bogs. They can be divided into running waters (rivers, streams) and standing waters (lakes, ponds, marshes, bogs). Although some organisms are found across most of these habitat types,
1911-509: A similarly rich fauna of invertebrates as a more varied habitat. The monotypic habitat occurs in both botanical and zoological contexts. Some invasive species may create monocultural stands that prevent other species from growing there. A dominant colonization can occur from retardant chemicals exuded, nutrient monopolization, or from lack of natural controls, such as herbivores or climate, that keep them in balance with their native habitat types. The yellow starthistle, Centaurea solstitialis
SECTION 20
#17328525455632002-538: A single mass. Each time pollination succeeds, thousands of ovules can be fertilized. Pollinators are often visually attracted by the shape and colours of the labellum. However, some Bulbophyllum species attract male fruit flies ( Bactrocera and Zeugodacus spp.) solely via a floral chemical which simultaneously acts as a floral reward (e.g. methyl eugenol , raspberry ketone , or zingerone ) to perform pollination. The flowers may produce attractive odours. Although absent in most species, nectar may be produced in
2093-492: A single species but to multiple species living in the same area. For example, terrestrial habitat types include forest , steppe , grassland , semi-arid or desert . Fresh-water habitat types include marshes , streams , rivers , lakes , and ponds ; marine habitat types include salt marshes, the coast, the intertidal zone , estuaries , reefs , bays, the open sea, the sea bed, deep water and submarine vents . Habitat types may change over time. Causes of change may include
2184-628: A sticky disc near the top of the column. Just below the pollinia is a second, larger sticky plate called the stigma . The complex mechanisms that orchids have evolved to achieve cross-pollination were investigated by Charles Darwin and described in Fertilisation of Orchids (1862). Orchids have developed highly specialized pollination systems, thus the chances of being pollinated are often scarce, so orchid flowers usually remain receptive for very long periods, rendering unpollinated flowers long-lasting in cultivation. Most orchids deliver pollen in
2275-498: A variety of bacteria and fungi; and snowfields on which algae grow. Whether from natural processes or the activities of man, landscapes and their associated habitat types change over time. There are the slow geomorphological changes associated with the geologic processes that cause tectonic uplift and subsidence , and the more rapid changes associated with earthquakes, landslides, storms, flooding, wildfires, coastal erosion , deforestation and changes in land use. Then there are
2366-441: A violent event (such as the eruption of a volcano , an earthquake , a tsunami , a wildfire or a change in oceanic currents); or change may occur more gradually over millennia with alterations in the climate , as ice sheets and glaciers advance and retreat, and as different weather patterns bring changes of precipitation and solar radiation . Other changes come as a direct result of human activities, such as deforestation ,
2457-423: A wide range of Brassicas and various other plant species, and it thrives in any open location with diverse plant associations. The large blue butterfly Phengaris arion is much more specific in its requirements; it is found only in chalk grassland areas, its larvae feed on Thymus species, and because of complex life cycle requirements it inhabits only areas in which Myrmica ants live. Disturbance
2548-562: Is chemosynthesis , a process by which microbes convert such substances as hydrogen sulfide or ammonia into organic molecules. These bacteria and Archaea are the primary producers in these ecosystems and support a diverse array of life. About 350 species of organism, dominated by molluscs , polychaete worms and crustaceans , had been discovered around hydrothermal vents by the end of the twentieth century, most of them being new to science and endemic to these habitat types. Besides providing locomotion opportunities for winged animals and
2639-404: Is a concept sometimes used in conservation biology , in which a single species of animal or plant is the only species of its type to be found in a specific habitat and forms a monoculture . Even though it might seem such a habitat type is impoverished in biodiversity as compared with polytypic habitat types, this is not necessarily the case. Monocultures of the exotic plant Hydrilla support
2730-418: Is a pastel pink orchid with leaves spotted dark green and light green. The jewel orchid ( Ludisia discolor ) is grown more for its colorful leaves than its white flowers. Some orchids, such as Dendrophylax lindenii (ghost orchid), Aphyllorchis and Taeniophyllum depend on their green roots for photosynthesis and lack normally developed leaves, as do all of the heterotrophic species. Orchids of
2821-509: Is a vigorous grass from Europe which has been introduced to the United States where it has become invasive. It is highly adapted to fire, producing large amounts of flammable detritus and increasing the frequency and intensity of wildfires. In areas where it has become established, it has altered the local fire regimen to such an extant that native plants cannot survive the frequent fires, allowing it to become even more dominant. A marine example
Holcoglossum - Misplaced Pages Continue
2912-417: Is achieved by removing the pollinia with a small instrument such as a toothpick from the pollen parent and transferring them to the seed parent. Some orchids mainly or totally rely on self-pollination , especially in colder regions where pollinators are particularly rare. The caudicles may dry up if the flower has not been visited by any pollinator, and the pollinia then fall directly on the stigma. Otherwise,
3003-494: Is evidence of nitrogen fixation in clouds , and less clear evidence of carbon cycling, both facilitated by microbial activity. There are other examples of extreme habitat types where specially adapted lifeforms exist; tar pits teeming with microbial life; naturally occurring crude oil pools inhabited by the larvae of the petroleum fly ; hot springs where the temperature may be as high as 71 °C (160 °F) and cyanobacteria create microbial mats ; cold seeps where
3094-559: Is important in the creation of biodiverse habitat types. In the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Wildflower meadows are sometimes created by conservationists but most of the flowering plants used are either annuals or biennials and disappear after a few years in the absence of patches of bare ground on which their seedlings can grow. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill
3185-542: Is in constant flux, as new studies continue to clarify the relationships between species and groups of species, allowing more taxa at several ranks to be recognized. The Orchidaceae is currently placed in the order Asparagales by the APG III system of 2009. Five subfamilies are recognised. The cladogram below was made according to the APG system of 1998. It represents the view that most botanists had held up to that time. It
3276-592: Is often called a backbulb. Backbulbs still hold nutrition for the plant, but then a pseudobulb usually takes over, exploiting the last reserves accumulated in the backbulb, which eventually dies off, too. A pseudobulb typically lives for about five years. Orchids without noticeable pseudobulbs are also said to have growths, an individual component of a sympodial plant. Like most monocots , orchids generally have simple leaves with parallel veins , although some Vanilloideae have reticulate venation . Leaves may be ovate, lanceolate, or orbiculate, and very variable in size on
3367-510: Is one of the two largest families of flowering plants, along with the Asteraceae . It contains about 28,000 currently accepted species distributed across 763 genera . The Orchidaceae family encompasses about 6–11% of all species of seed plants . The largest genera are Bulbophyllum (2,000 species), Epidendrum (1,500 species), Dendrobium (1,400 species) and Pleurothallis (1,000 species). It also includes Vanilla (the genus of
3458-422: Is spread out over a large area and is parallel to the gynostemium. The lip is shaped to allow potential pollinators to depress the middle lip. The flowers have an elongated spur, which is strongly reduced in the subgenus Brachycentron. The gynostemium has a large scar area. The stamen contains two separate pollina. The stipes connecting the pollina and the adhesive disc (Viscidium) bend in the middle when removed from
3549-416: Is the small-scale physical requirements of a particular organism or population. Every habitat includes large numbers of microhabitat types with subtly different exposure to light, humidity, temperature, air movement, and other factors. The lichens that grow on the north face of a boulder are different from those that grow on the south face, from those on the level top, and those that grow on the ground nearby;
3640-419: Is used as a food reserve for wintry periods, and provides for the development of the other one, from which visible growth develops. In warm and constantly humid climates, many terrestrial orchids do not need pseudobulbs. Epiphytic orchids, those that grow upon a support, have modified aerial roots that can sometimes be a few meters long. In the older parts of the roots, a modified spongy epidermis , called
3731-503: Is very challenging to research, and as well as being little-studied, it is vast, with 79% of the Earth's biosphere being at depths greater than 1,000 m (3,300 ft). With no plant life, the animals in this zone are either detritivores , reliant on food drifting down from surface layers, or they are predators, feeding on each other. Some organisms are pelagic , swimming or drifting in mid-ocean, while others are benthic, living on or near
Holcoglossum - Misplaced Pages Continue
3822-468: Is when sea urchin populations " explode " in coastal waters and destroy all the macroalgae present. What was previously a kelp forest becomes an urchin barren that may last for years and this can have a profound effect on the food chain . Removal of the sea urchins, by disease for example, can result in the seaweed returning, with an over-abundance of fast-growing kelp. Habitat destruction (also termed habitat loss and habitat reduction) occurs when
3913-550: The Latin habitāre , to inhabit, from habēre , to have or to hold. Habitat can be defined as the natural environment of an organism , the type of place in which it is natural for it to live and grow. It is similar in meaning to a biotope ; an area of uniform environmental conditions associated with a particular community of plants and animals. The chief environmental factors affecting the distribution of living organisms are temperature, humidity, climate, soil and light intensity , and
4004-400: The family Orchidaceae ( / ˌ ɔːr k ɪ ˈ d eɪ s i . iː , - s i . aɪ / ), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Earth except glaciers . The world's richest diversity of orchid genera and species is found in the tropics . Orchidaceae
4095-502: The methane and hydrogen sulfide issue from the ocean floor and support microbes and higher animals such as mussels which form symbiotic associations with these anaerobic organisms ; salt pans that harbour salt-tolerant bacteria , archaea and also fungi such as the black yeast Hortaea werneckii and basidiomycete Wallemia ichthyophaga ; ice sheets in Antarctica which support fungi Thelebolus spp., glacial ice with
4186-467: The photic zone in the oceans are relatively familiar habitat types. However the vast bulk of the ocean is inhospitable to air-breathing humans, with scuba divers limited to the upper 50 m (160 ft) or so. The lower limit for photosynthesis is 100 to 200 m (330 to 660 ft) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen (in some places), scarce food resources and extreme cold. This habitat
4277-454: The plowing of ancient grasslands, the diversion and damming of rivers, the draining of marshland and the dredging of the seabed. The introduction of alien species can have a devastating effect on native wildlife – through increased predation , through competition for resources or through the introduction of pests and diseases to which the indigenous species have no immunity. The word "habitat" has been in use since about 1755 and derives from
4368-454: The vanilla plant ), the type genus Orchis , and many commonly cultivated plants such as Phalaenopsis and Cattleya . Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced many hybrids and cultivars . Orchids are easily distinguished from other plants, as they share some very evident derived characteristics or synapomorphies . Among these are: bilateral symmetry of
4459-428: The accumulation of growth hormones at that point. These shoots are known as keiki . Epipogium aphyllum exhibits a dual reproductive strategy, engaging in both sexual and asexual seed production. The likelihood of apomixis playing a substantial role in successful reproduction appears minimal. Within certain petite orchid species groups, there is a noteworthy preparation of female gametes for fertilization preceding
4550-499: The act of pollination. The ovary typically develops into a capsule that is dehiscent by three or six longitudinal slits, while remaining closed at both ends. The seeds are generally almost microscopic and very numerous, in some species over a million per capsule. After ripening, they blow off like dust particles or spores. Most orchid species lack endosperm in their seed and must enter symbiotic relationships with various mycorrhizal basidiomyceteous fungi that provide them
4641-436: The animals and plants reliant on that habitat suffer. Many countries have enacted legislation to protect their wildlife. This may take the form of the setting up of national parks, forest reserves and wildlife reserves, or it may restrict the activities of humans with the objective of benefiting wildlife. The laws may be designed to protect a particular species or group of species, or the legislation may prohibit such activities as
SECTION 50
#17328525455634732-541: The anther may rotate and then enter the stigma cavity of the flower (as in Holcoglossum amesianum ). The slipper orchid Paphiopedilum parishii reproduces by self-fertilization . This occurs when the anther changes from a solid to a liquid state and directly contacts the stigma surface without the aid of any pollinating agent or floral assembly. The labellum of the Cypripedioideae is poke bonnet-shaped , and has
4823-400: The availability of food and the presence or absence of predators . Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior of a stem,
4914-416: The changes in habitat types brought on by alterations in farming practices, tourism, pollution, fragmentation and climate change. Loss of habitat is the single greatest threat to any species. If an island on which an endemic organism lives becomes uninhabitable for some reason, the species will become extinct . Any type of habitat surrounded by a different habitat is in a similar situation to an island. If
5005-455: The collecting of bird eggs, the hunting of animals or the removal of plants. A general law on the protection of habitat types may be more difficult to implement than a site specific requirement. A concept introduced in the United States in 1973 involves protecting the critical habitat of endangered species , and a similar concept has been incorporated into some Australian legislation. International treaties may be necessary for such objectives as
5096-420: The edge of each forest fragment, increased light encourages secondary growth of fast-growing species and old growth trees are more vulnerable to logging as access is improved. The birds that nest in their crevices, the epiphytes that hang from their branches and the invertebrates in the leaf litter are all adversely affected and biodiversity is reduced. Habitat fragmentation can be ameliorated to some extent by
5187-537: The flower ( zygomorphism ), many resupinate flowers, a nearly always highly modified petal (labellum), fused stamens and carpels , and extremely small seeds . All orchids are perennial herbs that lack any permanent woody structure. They can grow according to two patterns: Terrestrial orchids may be rhizomatous or form corms or tubers . The root caps of terrestrial orchids are smooth and white. Some sympodial terrestrial orchids, such as Orchis and Ophrys , have two subterranean tuberous roots . One
5278-536: The flower develops, it undergoes a twisting through 180°, called resupination , so that the labellum lies below the column . The labellum functions to attract insects, and in resupinate flowers, also acts as a landing stage, or sometimes a trap. The reproductive parts of an orchid flower are unique in that the stamens and style are joined to form a single structure, the column . Instead of being released singly, thousands of pollen grains are contained in one or two bundles called pollinia that are attached to
5369-436: The flower, it pulls the pollinium out of the anther, as it is connected to the viscidium by the caudicle or stipe. The caudicle then bends and the pollinium is moved forwards and downwards. When the pollinator enters another flower of the same species, the pollinium has taken such position that it will stick to the stigma of the second flower, just below the rostellum, pollinating it. In horticulture, artificial orchid pollination
5460-409: The flowers to gather volatile chemicals they require to synthesize pheromonal attractants. Males of such species as Euglossa imperialis or Eulaema meriana have been observed to leave their territories periodically to forage for aromatic compounds, such as cineole, to synthesize pheromone for attracting and mating with females. Each type of orchid places the pollinia on a different body part of
5551-510: The function of trapping visiting insects. The only exit leads to the anthers that deposit pollen on the visitor. In some extremely specialized orchids, such as the Eurasian genus Ophrys , the labellum is adapted to have a colour, shape, and odour which attracts male insects via mimicry of a receptive female. Pollination happens as the insect attempts to mate with flowers. Many neotropical orchids are pollinated by male orchid bees , which visit
SECTION 60
#17328525455635642-745: The gaps created. Similarly, coastal habitat types can become dominated by kelp until the seabed is disturbed by a storm and the algae swept away, or shifting sediment exposes new areas for colonisation. Another cause of disturbance is when an area may be overwhelmed by an invasive introduced species which is not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands, wetlands and deserts. Within these broad biomes are more specific habitat types with varying climate types, temperature regimes, soils, altitudes and vegetation. Many of these habitat types grade into each other and each one has its own typical communities of plants and animals. A habitat-type may suit
5733-430: The genus Corallorhiza (coralroot orchids) lack leaves altogether and instead have symbiotic or parasitic associations with fungal mycelium, though which they absorb sugars. Orchid flowers have three sepals , three petals and a three-chambered ovary . The three sepals and two of the petals are often similar to each other but one petal is usually highly modified, forming a "lip" or labellum . In most orchid genera, as
5824-534: The genus is Assam , Bangladesh , East Himalaya, Tibet , south-central and south-east China, Hainan , Taiwan , Laos , Myanmar , Cambodia , Thailand , and Vietnam . Many of the species come from the Yunnan province in the south-west of the People's Republic of China. Holcoglossum quasipinifolium and Holcoglossum pumilum are endemic to Taiwan. The species live at higher altitudes between 1200 m and 3300 m and thus prefer
5915-455: The individual plant. Their characteristics are often diagnostic. They are normally alternate on the stem, often folded lengthwise along the centre ("plicate"), and have no stipules . Orchid leaves often have siliceous bodies called stegmata in the vascular bundle sheaths (not present in the Orchidoideae ) and are fibrous. The structure of the leaves corresponds to the specific habitat of
6006-401: The largest orchid in the world, Grammatophyllum speciosum (giant orchid), it can reach three meters. Some Dendrobium species have long, canelike pseudobulbs with short, rounded leaves over the whole length; some other orchids have hidden or extremely small pseudobulbs, completely included inside the leaves. With ageing the pseudobulb sheds its leaves and becomes dormant. At this stage it
6097-415: The leaf tip. The root tips of living roots show a reddish color in all species of the genus, and some species also have red-spotted foliage. The flowering stem emerges laterally from the shoot axis and forms two or more flowers, which are far apart and form a raceme or inflorescence. The flowers are white and wide open. The lip is three-lobed. The lateral lobes are erect and dotted adaxially. The central part
6188-720: The lichens growing in the grooves and on the raised surfaces are different from those growing on the veins of quartz. Lurking among these miniature "forests" are the microfauna , species of invertebrate , each with its own specific habitat requirements. There are numerous different microhabitat types in a wood; coniferous forest, broad-leafed forest, open woodland, scattered trees, woodland verges, clearings, and glades; tree trunk, branch, twig, bud, leaf, flower, and fruit; rough bark, smooth bark, damaged bark, rotten wood, hollow, groove, and hole; canopy, shrub layer, plant layer, leaf litter , and soil; buttress root, stump, fallen log, stem base, grass tussock, fungus, fern, and moss. The greater
6279-531: The majority have more specific requirements. The water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools, bayous and backwaters which provide a range of habitat types. Similarly, aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marginal plants provide important habitat for both invertebrates and vertebrates, and submerged plants provide oxygenation of
6370-418: The necessary nutrients to germinate, so almost all orchid species are mycoheterotrophic during germination and reliant upon fungi to complete their lifecycles. Only a handful of orchid species have seed that can germinate without mycorrhiza , namely the species within the genus Disa with hydrochorous seeds. As the chance for a seed to meet a suitable fungus is very small, only a minute fraction of all
6461-515: The needs of the local residents for food, fuel and other resources. Faced with hunger and destitution, a farmer is likely to plough up a level patch of ground despite it being the last suitable habitat for an endangered species such as the San Quintin kangaroo rat , and even kill the animal as a pest. In the interests of ecotourism it is desirable that local communities are educated on the uniqueness of their flora and fauna. A monotypic habitat type
6552-658: The plant. Species that typically bask in sunlight, or grow on sites which can be occasionally very dry, have thick, leathery leaves and the laminae are covered by a waxy cuticle to retain their necessary water supply. Shade-loving species, on the other hand, have long, thin leaves. The leaves of most orchids are perennial, that is, they live for several years, while others, especially those with plicate leaves as in Catasetum , shed them annually and develop new leaves together with new pseudobulbs. The leaves of some orchids are considered ornamental. The leaves of Macodes sanderiana ,
6643-512: The plants are regularly exposed to hoarfrost during the flowering period, which they survive without any problems. A successful culture often fails because the culture is permanently too warm or because the substrate is too fine, in which the roots die off due to the lack of air. The following intergeneric hybrids with Holcoglossum are listed with the Royal Horticultural Society. Orchid Orchids are plants that belong to
6734-419: The presence or absence of all the requirements that the organism needs to sustain it. Generally speaking, animal communities are reliant on specific types of plant communities. Some plants and animals have habitat requirements which are met in a wide range of locations. The small white butterfly Pieris rapae for example is found on all the continents of the world apart from Antarctica . Its larvae feed on
6825-545: The proteins the flexibility they need. There are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. Hydrothermal vents were first discovered in the ocean depths in 1977. They result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. The under-water hot springs may gush forth at temperatures of over 340 °C (640 °F) and support unique communities of organisms in their immediate vicinity. The basis for this teeming life
6916-428: The provision of wildlife corridors connecting the fragments. These can be a river, ditch, strip of trees, hedgerow or even an underpass to a highway. Without the corridors, seeds cannot disperse and animals, especially small ones, cannot travel through the hostile territory, putting populations at greater risk of local extinction . Habitat disturbance can have long-lasting effects on the environment. Bromus tectorum
7007-573: The rocky seabed have found microbial communities apparently based on the products of reactions between water and the constituents of rocks. These communities have not been studied much, but may be an important part of the global carbon cycle . Rock in mines two miles deep also harbour microbes; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. These metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. The intertidal zone and
7098-557: The rostellum. The rostellum is deeply incised. The number of chromosomes is 2n = 38 in almost all species. Holcoglossum tsii has 76 chromosomes in the diploid chromosome set (2n = 76). Self-pollination has been observed in Holcoglossum amesianum , in which the pollina moves independently to the fertile stigma in the column. As of July 2024, Plants of the World Online accepted the following species: The native distribution area of
7189-565: The seabed. Their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. A number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. In general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure-resistant biomolecules and small organic molecules present in their cells known as piezolytes , which give
7280-400: The seeds of which survive the drought, but also some uniquely adapted perennials. Animals adapted to these extreme habitat types also exist; fairy shrimps can lay "winter eggs" which are resistant to desiccation , sometimes being blown about with the dust, ending up in new depressions in the ground. These can survive in a dormant state for as long as fifteen years. Some killifish behave in
7371-417: The seeds released grow into adult plants. In cultivation, germination typically takes weeks. Horticultural techniques have been devised for germinating orchid seeds on an artificial nutrient medium, eliminating the requirement of the fungus for germination and greatly aiding the propagation of ornamental orchids. The usual medium for the sowing of orchids in artificial conditions is agar gel combined with
7462-519: The setting up of marine reserves. Another international agreement, the Convention on the Conservation of Migratory Species of Wild Animals , protects animals that migrate across the globe and need protection in more than one country. Even where legislation protects the environment, a lack of enforcement often prevents effective protection. However, the protection of habitat types needs to take into account
7553-528: The southeastern United States. Its first intermediate host is a snail and the second, a glass shrimp . The final host is the waterfowl or mammal that consumes the shrimp. Although the vast majority of life on Earth lives in mesophyllic (moderate) environments, a few organisms, most of them microbes , have managed to colonise extreme environments that are unsuitable for more complex life forms. There are bacteria , for example, living in Lake Whillans , half
7644-419: The stem of sympodial epiphytes, or in some species essentially the entire stem, may be thickened to form a pseudobulb that contains nutrients and water for drier periods. The pseudobulb typically has a smooth surface with lengthwise grooves, and can have different shapes, often conical or oblong. Its size is very variable; in some small species of Bulbophyllum , it is no longer than two millimeters, while in
7735-554: The structural diversity in the wood, the greater the number of microhabitat types that will be present. A range of tree species with individual specimens of varying sizes and ages, and a range of features such as streams, level areas, slopes, tracks, clearings, and felled areas will provide suitable conditions for an enormous number of biodiverse plants and animals. For example, in Britain it has been estimated that various types of rotting wood are home to over 1700 species of invertebrate. For
7826-403: The substrate should be quite fine in order to be able to nourish the tender roots. The large species of the subgenus Brachycentron and section Holcoglossum can be cultivated in a tether but are best suited to basket or pot culture. An exception is Holcoglossum subulifolium , which is better tied up due to its hanging growth. If regular watering is ensured, these species are best cultivated in
7917-473: The survival and reproduction of a particular species . A species habitat can be seen as the physical manifestation of its ecological niche . Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil , moisture , range of temperature , and light intensity . Biotic factors include
8008-455: The town's features to make their homes. Rats and mice have followed man around the globe, pigeons , peregrines , sparrows , swallows and house martins use the buildings for nesting, bats use roof space for roosting, foxes visit the garbage bins and squirrels , coyotes , raccoons and skunks roam the streets. About 2,000 coyotes are thought to live in and around Chicago . A survey of dwelling houses in northern European cities in
8099-418: The twentieth century found about 175 species of invertebrate inside them, including 53 species of beetle, 21 flies, 13 butterflies and moths, 13 mites, 9 lice, 7 bees, 5 wasps, 5 cockroaches, 5 spiders, 4 ants and a number of other groups. In warmer climates, termites are serious pests in the urban habitat; 183 species are known to affect buildings and 83 species cause serious structural damage. A microhabitat
8190-460: The water, absorb nutrients and play a part in the reduction of pollution. Rivers Ponds Lakes Marine habitats include brackish water, estuaries, bays, the open sea, the intertidal zone, the sea bed, reefs and deep / shallow water zones. Further variations include rock pools , sand banks , mudflats , brackish lagoons, sandy and pebbly beaches, and seagrass beds, all supporting their own flora and fauna. The benthic zone or seabed provides
8281-594: Was supported by morphological studies , but never received strong support in molecular phylogenetic studies. Apostasioideae : 2 genera and 16 species, south-eastern Asia Cypripedioideae : 5 genera and 130 species, from the temperate regions of the world, as well as tropical America and tropical Asia Vanilloideae : 15 genera and 180 species, humid tropical and subtropical regions, eastern North America Epidendroideae : more than 500 genera and more or less 20,000 species, cosmopolitan Orchidoideae : 208 genera and 3,630 species, cosmopolitan In 2015,
#562437