Asparagales
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
Orchidaceae
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
Bidens
Bidens is a genus of flowering plants in the aster family, Asteraceae. The common names beggarticks, black jack, burr marigolds, cobbler's pegs, Spanish needles, stickseeds and tickseed sunflowers refer to the fruits of the plants, most of which are bristly and barbed, with two sharp pappi at the end; the generic name refers to the same character. The plants are zoochorous; this has enabled them to colonize a wide range, including many oceanic islands. Some of these species occur only in a restricted range and several are now threatened with extinction, notably in the Hawaiian Islands. Due to the absence of native mammals on these islands, some of the oceanic island taxa have reduced burrs, evolving features that seem to aid in dispersal by the wind instead. Bidens is distributed throughout the warm temperate regions of the world. Most species occur in the Americas and Polynesia, there are some in Europe and Asia. Bidens is related to the American genus Coreopsis, the genera are sometimes difficult to tell apart.
On the Hawaiian Islands, Bidens are called koʻokoʻolau. Nodding beggarticks and hairy beggarticks are useful as honey plants. Several Bidens species are used as food by the caterpillars of certain Lepidoptera, such as the noctuid moth Hypercompe hambletoni and the brush-footed butterfly Vanessa cardui, the painted lady; the Bidens mottle virus, a plant pathogen, was first isolated from B. pilosa, it infects many other Asteraceae and plants of other families. The taxonomy of Bidens has been described as "chaotic", it is not clear how many taxa are included in its bounds. There are at least 150 to 250 species, some estimates fall around 230. Species include: Bidens alba DC. – romerillo Bidens amplectens Sherff – Waiʻanae kokoʻolau Bidens amplissima Greene – Vancouver Island beggarticks Bidens aristosa Britt. – bearded beggarticks, long-bracted beggarticks, tickseed sunflower, western tickseed Bidens asymmetrica Sherff – Koʻolau kokoʻolau, Ko'olau Range beggarticks Bidens aurea Sherff – Arizona beggarticks Bidens beckii – Beck's water-marigold, Henderson's water-marigold, Oregon water-marigold Bidens bidentoides Britt.
– Delmarva beggarticks Bidens bigelovii A. Gray – Bigelow's beggarticks Bidens bipinnata L. – Spanish needles, hemlock beggarticks, gui zheng cao Bidens biternata Bidens cabopulmensis Bidens campylotheca Sch. Bip.– viper beggarticks Bidens cernua L. – nodding beggarticks, nodding bur-marigold Bidens cervicata Sherff – Kauaʻi beggarticks Bidens chippii Mesfin Bidens conjuncta Sherff – bog beggarticks Bidens connata Muhl. Ex Willd. – purplestem beggarticks Bidens coronata Britt. – crowned beggarticks Bidens cosmoides Sherff – cosmosflower beggarticks, poʻola nui Bidens cynapiifolia Kunth – West Indian beggarticks, alfilerillo Bidens discoidea Britt. – discoid beggarticks, small beggarticks, swamp beggarticks, few-bracted beggarticks Bidens eatonii Fern. – Eaton's beggarticks, bident d'Eaton Bidens ferulifolia DC. – Apache beggarticks, fern-leaved beggarticks Bidens forbesii Sherff – coastal bluff beggarticks Bidens frondosa L. – devil's beggarticks, devil's pitchfork, devil's bootjack, pitchfork weed, common beggarticks, sticktights.
Pitchfork weed is considered to be a weed in New Zealand. Bidens gardneri Baker – ridge beggarticks Bidens hawaiensis A. Gray – Hawaiʻi beggarticks Bidens henryi Sherff Bidens heterodoxa Fern. & H. St. John – Connecticut beggarticks, bident différent Bidens heterosperma Gray – Rocky Mountain beggarticks Bidens hillebrandiana O. Deg. – seacliff beggarticks Bidens hyperborea Greene – estuary beggarticks, coastal beggarticks, northern estuarine beggarticks, seacliff beggarticks Bidens laevis B. S. P. – smooth beggarticks, smooth bur-marigold, larger bur-marigold. Smooth beggarticks is a common fall flower in the southeastern United States. Bidens lemmonii Gray – Lemmon's beggarticks Bidens leptocephala Sherff – few-flowered beggarticks Bidens leptophylla Bidens macrocarpa Sherff – large-fruited beggarticks Bidens mannii T. G. J. Rayner Bidens mauiensis Sherff – Maui beggarticks Bidens maximowicziana Bidens menziesii Sherff – Mauna Loa beggarticks Bidens meyeri V. A. Funk & K. R. Wood Bidens micrantha Gaud. – grassland beggarticks B. micrantha ssp. kalealaha Nagata & Ganders – Kalealaha beggarticks Bidens mitis Sherff – small-fruited beggarticks Bidens molokaiensis Sherff – Molokaʻi beggarticks, wedge beggarticks Bidens × multiceps Fassett Bidens parviflora Bidens pachyloma – Meskel Flower Bidens pilosa S.
F. Blake – hairy beggarticks Bidens polylepis S. F. Blake Bidens populifolia Sherff – Oʻahu beggarticks Bidens radiata Bidens reptans G. Don – manzanilla trepador Bidens sandvicensis Less. – shrubland beggarticks Bidens schimperi Sch. Bip. Bidens simplicifolia C. H. Wright Bidens socorrensis Bidens squarrosa Kunth Bidens subalternans DC. Bidens tenuisecta A. Gray – slim-lobed beggarticks Bidens torta Sherff – corkscrew beggarticks Bidens trichosperma Britton – crowned beggarticks Bidens tripartita L. – three-lobed beggarticks, three-part beggarticks, leafy-bracted beggarticks, trifid bur-marigold Bidens triplinervia Kunth B. triplinervia var. macrantha Sherff Bidens valida Sherff – Mt. Kahili beggarticks Bidens vulgata Greene – big devil's beggarticks, tall beggarticks, tall bur-marigold, western sticktight Bidens wiebkei Sherff – Wiebke's beggarticks Cosmos atrosanguineus Voss (as B. atrosanguinea
Asteraceae
Asteraceae or Compositae is a large and widespread family of flowering plants. The family has 32,913 accepted species names, in 1,911 genera and 13 subfamilies. In terms of numbers of species, the Asteraceae are rivaled only by the Orchidaceae.. Nearly all members bear their flowers in dense heads surrounded by involucral bracts; when viewed from a distance, each capitulum may have the appearance of being a single flower. Enlarged outer flowers in the capitula may resemble petals, the involucral bracts may look like a calyx; the name Asteraceae comes from the type genus Aster, from the Ancient Greek ἀστήρ, meaning star, refers to the star-like form of the inflorescence. Compositae is an older name that refers to the "composite" nature of the capitula, which consist of many individual flowers. Most members of Asteraceae are annual or perennial herbs, but a significant number are shrubs, vines, or trees; the family has a worldwide distribution, from the polar regions to the tropics, colonizing a wide variety of habitats.
It is most common in the semiarid regions of subtropical and lower temperate latitudes. The Asteraceae may represent as much as 10% of autochthonous flora in many regions of the world. Asteraceae is an economically important family, providing products such as cooking oils, sunflower seeds, sweetening agents, coffee substitutes and herbal teas. Several genera are of horticultural importance, including pot marigold, Calendula officinalis, various daisies, chrysanthemums, dahlias and heleniums. Asteraceae are important in herbal medicine, including Grindelia and many others. A number of species are considered invasive, most notably in North America, introduced by European settlers who used the young leaves as a salad green; the study of this family is known as synantherology. The name Asteraceae comes to international scientific vocabulary from New Latin, from Aster, the type genus, + -aceae, a standardized suffix for plant family names in modern taxonomy; the genus name comes from the Classical Latin word aster, "star", which came from Ancient Greek ἀστήρ, "star".
Compositae means "composite" and refers to the characteristic inflorescence, a special type of pseudanthium found in only a few other angiosperm families. The vernacular name daisy applied to members of this family, is derived from the Old English name of the daisy: dæġes ēaġe, meaning "day's eye"; this is because the petals close at dusk. Asteraceae species have a cosmopolitan distribution, are found everywhere except Antarctica and the extreme Arctic, they are numerous in tropical and subtropical regions. Compositae, the original name for Asteraceae, were first described in 1792 by the German botanist Paul Dietrich Giseke. Traditionally, two subfamilies were recognised: Cichorioideae; the latter has been shown to be extensively paraphyletic, has now been divided into 12 subfamilies, but the former still stands. The phylogenetic tree presented below is based on Panero & Funk updated in 2014, now includes the monotypic Famatinanthoideae; the diamond denotes a poorly supported node, the dot a poorly supported node.
It is noteworthy that the four subfamilies Asteroideae, Cichorioideae and Mutisioideae contain 99% of the species diversity of the whole family. Because of the morphological complexity exhibited by this family, agreeing on generic circumscriptions has been difficult for taxonomists; as a result, several of these genera have required multiple revisions. Members of the Asteraceae are herbaceous plants, but some shrubs and trees do exist, they are easy to distinguish from other plants because of their characteristic inflorescence and other shared characteristics. However, determining genera and species of some groups such as Hieracium is notoriously difficult. Members of the Asteraceae produce taproots, but sometimes they possess fibrous root systems. Stems are herbaceous aerial branched cylindrical with glandular hairs erect but can be prostrate to ascending; some species have underground stems in the form of rhizomes. These can be woody depending on the species; the leaves and the stems often contain secretory canals with resin or latex.
The leaves can be opposite, or whorled. They may be simple, but are deeply lobed or otherwise incised conduplicate or revolute; the margins can be entire or toothed. In plants of the family Asteraceae, what appears to be a single flower is a cluster of much smaller flowers; the overall appearance of the cluster, as a single flower, functions in attracting pollinators in the same way as the structure of an individual flower in some other plant families. The older family name, comes from the fact that what appears to be a single flower is a composite of smaller flowers; the "petals" or "sunrays" in a sunflower head are individual strap-sha
