Asparagales is an order of plants in modern classification systems such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. The order takes its name from the type family Asparagaceae and is placed in the monocots amongst the lilioid monocots; the order has only been recognized in classification systems. It was first put forward by Huber in 1977 and taken up in the Dahlgren system of 1985 and the APG in 1998, 2003 and 2009. Before this, many of its families were assigned to the old order Liliales, a large order containing all monocots with colourful tepals and lacking starch in their endosperm. DNA sequence analysis indicated that many of the taxa included in Liliales should be redistributed over three orders, Liliales and Dioscoreales; the boundaries of the Asparagales and of its families have undergone a series of changes in recent years. In the APG circumscription, Asparagales is the largest order of monocots with 14 families, 1,122 genera, about 36,000 species; the order is circumscribed on the basis of molecular phylogenetics, but is difficult to define morphologically, since its members are structurally diverse.
Most species of Asparagales are herbaceous perennials, although some are climbers and some are tree-like. The order contains many geophytes. According to telomere sequence, at least two evolutionary switch-points happened within the order. Basal sequence is formed by TTTAGGG like in majority of higher plants. Basal motif was changed to vertebrate-like TTAGGG and the most divergent motif CTCGGTTATGGG appears in Allium. One of the defining characteristics of the order is the presence of phytomelanin, a black pigment present in the seed coat, creating a dark crust. Phytomelanin is found in most families of the Asparagales; the leaves of all species form a tight rosette, either at the base of the plant or at the end of the stem, but along the stem. The flowers are not distinctive, being'lily type', with six tepals and up to six stamina; the order is thought to have first diverged from other related monocots some 120–130 million years ago, although given the difficulty in classifying the families involved, estimates are to be uncertain.
From an economic point of view, the order Asparagales is second in importance within the monocots to the order Poales. Species are used as food and flavourings, as cut flowers, as garden ornamentals. Although most species in the order are herbaceous, some no more than 15 cm high, there are a number of climbers, as well as several genera forming trees, which can exceed 10 m in height. Succulent genera occur in several families. All species have a tight cluster of leaves, either at the base of the plant or at the end of a more-or-less woody stem as with Yucca. In some cases the leaves are produced along the stem; the flowers are in the main not distinctive, being of a general'lily type', with six tepals, either free or fused from the base and up to six stamina. They are clustered at the end of the plant stem; the Asparagales are distinguished from the Liliales by the lack of markings on the tepals, the presence of septal nectaries in the ovaries, rather than the bases of the tepals or stamen filaments, the presence of secondary growth.
They are geophytes, but with linear leaves, a lack of fine reticular venation. The seeds characteristically have the external epidermis either obliterated, or if present, have a layer of black carbonaceous phytomelanin in species with dry fruits; the inner part of the seed coat is collapsed, in contrast to Liliales whose seeds have a well developed outer epidermis, lack phytomelanin, display a cellular inner layer. The orders which have been separated from the old Liliales are difficult to characterize. No single morphological character appears to be diagnostic of the order Asparagales; the flowers of Asparagales are of a general type among the lilioid monocots. Compared to Liliales, they have plain tepals without markings in the form of dots. If nectaries are present, they are in the septa of the ovaries rather than at the base of the tepals or stamens; those species which have large dry seeds have a dark, crust-like outer layer containing the pigment phytomelan. However, some species with hairy seeds, berries, or reduced seeds lack this dark pigment in their seed coats.
Phytomelan is not unique to Asparagales but it is common within the order and rare outside it. The inner portion of the seed coat is completely collapsed. In contrast, the morphologically similar seeds of Liliales have no phytomelan, retain a cellular structure in the inner portion of the seed coat. Most monocots are unable to thicken their stems once they have formed, since they lack the cylindrical meristem present in other angiosperm groups. Asparagales have a method of secondary thickening, otherwise only found inDioscorea. In a process called'anomalous secondary growth', they are able to create new
The Orchidaceae are a diverse and widespread family of flowering plants, with blooms that are colourful and fragrant known as the orchid family. Along with the Asteraceae, they are one of the two largest families of flowering plants; the Orchidaceae have about 28,000 accepted species, distributed in about 763 genera. The determination of which family is larger is still under debate, because verified data on the members of such enormous families are continually in flux. Regardless, the number of orchid species nearly equals the number of bony fishes and is more than twice the number of bird species, about four times the number of mammal species; the family encompasses about 6–11% of all seed plants. The largest genera are Bulbophyllum, Epidendrum and Pleurothallis, it includes Vanilla–the genus of the vanilla plant, the type genus Orchis, many cultivated plants such as Phalaenopsis and Cattleya. Moreover, since the introduction of tropical species into cultivation in the 19th century, horticulturists have produced more than 100,000 hybrids and cultivars.
Orchids are distinguished from other plants, as they share some evident, shared derived characteristics, or synapomorphies. Among these are: bilateral symmetry of the flower, many resupinate flowers, a nearly always modified petal, fused stamens and carpels, small seeds. All orchids are perennial herbs, they can grow according to two patterns: Monopodial: The stem grows from a single bud, leaves are added from the apex each year and the stem grows longer accordingly. The stem of orchids with a monopodial growth can reach several metres in length, as in Vanda and Vanilla. Sympodial: Sympodial orchids have a front and a back; the plant produces a series of adjacent shoots, which grow to a certain size and stop growing and are replaced. Sympodial orchids grow laterally following the surface of their support; the growth continues by development of new leads, with their own leaves and roots, sprouting from or next to those of the previous year, as in Cattleya. While a new lead is developing, the rhizome may start its growth again from a so-called'eye', an undeveloped bud, thereby branching.
Sympodial orchids may have visible pseudobulbs joined by a rhizome, which creeps along the top or just beneath the soil. Terrestrial orchids may form corms or tubers; the root caps of terrestrial orchids are white. Some sympodial terrestrial orchids, such as Orchis and Ophrys, have two subterranean tuberous roots. One is used as a food reserve for wintry periods, provides for the development of the other one, from which visible growth develops. In warm and 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 velamen, has the function of absorbing humidity, it 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 come from mineral dust, organic detritus, animal droppings and other substances collecting among on their supporting surfaces. The base of the stem of sympodial epiphytes, or in some species the entire stem, may be thickened to form a pseudobulb that contains nutrients and water for drier periods; the pseudobulb has a smooth surface with lengthwise grooves, can have different shapes conical or oblong. Its size is variable; some Dendrobium species have long, canelike pseudobulbs with short, rounded leaves over the whole length. With ageing, the pseudobulb becomes dormant. At this stage, it is called a backbulb. Backbulbs still hold nutrition for the plant, but a pseudobulb takes over, exploiting the last reserves accumulated in the backbulb, which dies off, too. A pseudobulb lives for about five years. Orchids without noticeable pseudobulbs are said to have growths, an individual component of a sympodial plant. Like most monocots, orchids have simple leaves with parallel veins, although some Vanilloideae have reticulate venation.
Leaves may be ovate, lanceolate, or orbiculate, variable in size on the individual plant. Their characteristics are diagnostic, they are alternate on the stem folded lengthwise along the centre, have no stipules. Orchid leaves have siliceous bodies called stegmata in the vascular bundle sheaths and are fibrous; the structure of the leaves corresponds to the specific habitat of the plant. Species that bask in sunlight, or grow on sites which can be 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 thin leaves; the leaves of most orchids are perennial, that is, they live for several years, while others those with plicate leaves as in Catasetum, shed them annually and de
The tribe Epidendreae of the Orchidaceae comprises six subtribes: Bletiinae sensu MMIV, which contains only the genera Basiphyllaea and Hexalectris Chysinae Coeliinae Laeliinae Pleurothallidinae Ponerinae
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
Epidendrum, abbreviated Epi in the horticultural trade, is a large neotropical genus of the orchid family. With more than 1,500 species, some authors describe it as a mega-genus; the genus name refers to its epiphytic growth habit. When Carl Linnaeus named this genus in 1763, he included in this genus all the epiphytic orchids known to him. Although few of these orchids are still included in the genus Epidendrum, some species of Epidendrum are not epiphytic, they are native to the tropics and subtropical regions of the American continents, from North Carolina to Argentina. Their habitat can be epiphytic, terrestrial, or lithophytic. Many are grown at altitudes between 1,000 and 3,000 m, their habitats include humid jungles, dry tropical forests, sunny grassy slopes, cool cloud forests, sandy barrier islands. Members of this genus can be aggressive colonisers of disturbed habitat, many species which were once rare in this genus have become more common as the result of human activities. For example, some of these plants can be found in greater abundance growing terrestrially along road cuts throughout their native ranges as the result of road construction.
Many of these species are easy to grow in rich humus compost with some sand. The plants resemble Dendrobiums in form and habit although they tend to be terrestrial rather than lithophytic and epiphytic, do better in a humus rich, well aerated substrate. Most of the high altitude members of this genus from cloud forests defy cultivation outside their habitat, it is reported that moving a plant from one location to another on the same host tree in habitat will result in the death of the plant due to dependency on a specific mycorrhizal fungal symbiont, they are quite varied in flower appearance. They grow in racemose inflorescences, sometimes in corymbs or panicles; the apical, lateral or basal flowers are small to medium in size and are not marked by a conspicuous display. The inflorescences are dense. Many species are fragrant; the flowers may be produced during several years from the same or new inflorescences. The ellipsoid fruits are 3-ribbed capsules; this genus has the following characteristics: a slit rostellum, producing a transparent or white thick and adhesive liquid.
The sometimes fringed lip is adnate to the column. The genus Prosthechea was split off because the lip is not adnate to the apex of the column; the pollinarium contains four pollinia, sometimes two and eight pollinia, four reduced. The erect, pendent, or creeping stems are reed-like, simple or branching, or may be pseudobulbs or thickened stems. European taxonomists applied the generic epithet Epidendrum to all newly discovered epiphytic orchids. Many of these "Epidendrums" were recognized as being quite diverse and deserving of different generic epithets—many belong to different tribes or subtribes. To add to the confusion, many descriptions of related species were published with different generic epithets; as if the confusion caused by these publications were not great enough, many related genera have been recognized and published. According to the modern rules of taxonomy, each new proposed genus, split off from Epidendrum must bear the name of the oldest generic epithet published for a member of the new genus.
Hence, many genera which have been brought into synonymy with Epidendrum have been segregated out again. Because most of these decisions rest on the informed opinions of authorities, the segregated taxa are then re-published as synonyms. Hence, some of the following information may seem a bit contradictory if the assertion that two names are "synonyms" is misconstrued as an assertion that the two names mean the same thing; the following genera have been brought into synonymy with Epidendrum: Amphiglottis Salisb. Auliza Small Coilostylis Raf. Didothion Raf. Diothonea Lindl. Dothilophis Raf. Doxosma Raf. Epicladium Small Epidanthus L. O. Williams Epidendropsis Garay & Dunst. Exophya Raf. Hemiscleria Lindl. Kalopternix Garay & Dunst. Lanium Benth. Larnandra Raf. Microepidendrum Brieger Minicolumna Brieger Nanodes Lindl. Neolehmannia Kraenzl. Neowilliamsia Garay Nyctosma Raf. Phadrosanthus Neck. Ex Raf. Physinga Lindl. Pleuranthium Benth. Pseudepidendrum Rchb.f. Psilanthemum Klotzsch ex Stein Seraphyta Fisch. & C. A.
Mey. Spathiger Small Stenoglossum Kunth Tritelandra Raf.. Genera which have been erected from Epidendrum include the following examples: Anacheilium Withner & P. A. Harding; this genus contains more than 50 species, reclassified from Prosthechea and Epidendrum. Barkeria Dimerandra Caularthron Coilostylis Withner & Harding Encyclia This is another "mega-genus" differing from Epidendrum in that the plants are pseudobulbous, in that the lip "encircles" the column, rather than being adnate. Like Epidendrum, genera have been and are to continue to be split off from this genus. Euchile C. L. Withner was elevated from a section of Encyclia with two species. Hormidium Lindl. Ex Heynh, described by Brieger as having the lip adnate to the pro
Coilostylis ciliaris Epidendrum ciliare, is a species of orchid in the genus Coilostylis. It was transferred from Epidendrum by Withner and Harding in 2004, it is the type species of the genus Coilostylis. The diploid chromosome number of C. ciliare has been determined from several individuals as 2n = 40, 80, 160, the haploid chromosome number as n = 20. The moth Pseudosphinx tetrio has been observed as a pollinator in Puerto Rico
Coilostylis clavata Epidendrum purpurascens, is a species of orchid in the genus Coilostylis