Cynodon dactylon
Cynodon dactylon known as Vilfa stellata, Bermuda grass, Dhoob, dūrvā grass, dog's tooth grass, Bahama grass, devil's grass, couch grass, Indian doab, grama and scutch grass, is a grass that originated in Africa. Although it is not native to Bermuda, it is an abundant invasive species there, it is presumed to have arrived in North America from Bermuda. In Bermuda it has been known as crab grass; the blades are a grey-green colour and are short 2–15 cm long with rough edges. The erect stems can grow 1–30 cm tall; the stems are flattened tinged purple in colour. The seed heads are produced in a cluster of two to six spikes together at the top of the stem, each spike 2–5 cm long, it has a deep root system. The grass creeps along roots wherever a node touches the ground, forming a dense mat. C. dactylon reproduces through seeds and rhizomes. Growth begins at temperatures above 15 °C with optimum growth between 24 and 37 °C. Growth is retarded by full shade, e.g. close to tree trunks. Cynodon dactylon is cultivated in warm climates all over the world between about 30° S and 30° N latitude, that get between 625 and 1,750 mm of rainfall a year.
It is found in the U. S. in the southern half of the country and in warm climates. Control/eradication It is fast-growing and tough, making it popular and useful for sports fields, as when damaged it will recover quickly, it is a desirable turf grass in warm temperate climates for those regions where its heat and drought tolerance enable it to survive where few other grasses do. This combination makes it a frequent choice for golf courses in the southern and southeastern U. S, it has a coarse-bladed form with numerous cultivars selected for different turf requirements. It is highly aggressive, crowding out most other grasses and invading other habitats, has become a hard-to-eradicate weed in some areas; this weedy nature leads some gardeners to give it the name of "devil grass". Bermuda grass is difficult to control in flower beds and most herbicides do not work. However, Ornamec 170 and Turflon ester have shown some effectiveness as well as Imazapyr. All of these items are difficult to find in retail stores as they are marketed to professional landscapers.
Bermuda grass has been cultivated on saline soils in California's Central Valley which are too salt-damaged to support agricultural crops. The hybrid variety Tifton 85, like some other grasses, produces cyanide under certain conditions, has been implicated in several livestock deaths. Tifgreen Tifway 419 or Tifton 419 LaPaloma Riviera SR9554 Laprima Veracruz Wrangler Yukon AgriDark OZTUFF This list is not all inclusive. Hundreds of cultivars have been created for environmental tolerance and stakeholder requirements. New cultivars are released yearly. FAO.org factsheet: Cynodon dactylon Online field guide to common saltmarsh plants of Queensland
Lawn
A lawn is an area of soil-covered land planted with grasses and other durable plants such as clover which are maintained at a short height with a lawnmower and used for aesthetic and recreational purposes. Common characteristics of a lawn are that it is composed only of grass species, it is subject to weed and pest control, it is subject to practices aimed at maintaining its green color, it is mowed to ensure an acceptable length, although these characteristics are not binding as a definition. Lawns are used around houses, commercial buildings and offices. Many city parks have large lawn areas. In recreational contexts, the specialised names turf, field or green may be used, depending on the sport and the continent; the term "lawn", referring to a managed grass space, dates to no earlier than the 16th century. Tied to suburban expansion and the creation of the household aesthetic, the lawn is an important aspect of the interaction between the natural environment and the constructed urban and suburban space.
In many suburban areas, there are bylaws in place requiring houses to have lawns and requiring the proper maintenance of these lawns. In some jurisdictions where there are water shortages, local government authorities are encouraging alternatives to lawns to reduce water use. Lawn is a cognate of llan, derived from the Common Brittonic word landa that means heath, barren land, or clearing. Lawns may have originated as grassed enclosures within early medieval settlements used for communal grazing of livestock, as distinct from fields reserved for agriculture; the word "laune" is first attested in 1540, is related to the Celtic Brythonic word lan/llan/laun, which has the meaning of enclosure in relation to a place of worship. In medieval Europe, open expanses of low grasses became valued among the aristocracy because they allowed those inside an enclosed fence or castle to view those approaching. Lawns became popular with the aristocracy in northern Europe from the Middle Ages onward; the early lawns were not always distinguishable from pasture fields.
The damp climate of maritime Western Europe in the north made lawns possible to manage. They were not a part of gardens in other regions and cultures of the world until contemporary influence. Before the invention of mowing machines in 1830, lawns were managed differently, they were an element of wealthy estates and manor houses, in some places were maintained by the labor-intensive methods of scything and shearing. In most situations, they were pasture land maintained through grazing by sheep or other livestock. Areas of grass grazed by rabbits, horses or sheep over a long period form a low, tight sward similar to a modern lawn; this was the original meaning of the word "lawn", the term can still be found in place names. Some forest areas where extensive grazing is practiced still have these seminatural lawns. For example, in the New Forest, such grazed areas are common, are known as lawns, for example Balmer Lawn. Lawns similar to those of today first appeared in France and England in the 1700s when André Le Nôtre designed the gardens of Versailles that included a small area of grass called the tapis vert, or "green carpet".
It was not until the 17th and 18th century that the garden and the lawn became a place created first as walkways and social areas. They were made up of meadow plants, such as a particular favorite. In the early 17th century, the Jacobean epoch of gardening began. By the end of this period, the English lawn was a symbol of status of the gentry. In the early 18th century, landscape gardening for the aristocracy entered a golden age, under the direction of William Kent and Lancelot "Capability" Brown, they refined the English landscape garden style with the design of natural, or "romantic", estate settings for wealthy Englishmen. Brown, remembered as "England's greatest gardener", designed over 170 parks, many of which still endure, his influence was so great that the contributions to the English garden made by his predecessors Charles Bridgeman and William Kent are overlooked. His work still endures at Croome Court, Blenheim Palace, Warwick Castle, Harewood House, Bowood House, Milton Abbey, in traces at Kew Gardens and many other locations.
His style of smooth undulating lawns which ran seamlessly to the house and meadow, clumps and scattering of trees and his serpentine lakes formed by invisibly damming small rivers, were a new style within the English landscape, a "gardenless" form of landscape gardening, which swept away all the remnants of previous formally patterned styles. His landscapes were fundamentally different from what they replaced, the well-known formal gardens of England which were criticised by Alexander Pope and others from the 1710s; the open "English style" of parkland first spread across Britain and Ireland, across Europe, such as the garden à la française being replaced by the French landscape garden. By this time, the word "lawn" in England had semantically shifted to describe a piece of a garden covered with grass and mown. Wealthy families in America during the late 18th century began mimicking English landscaping styles. In 1780, the Shaker community began the first industrial production of high-quality grass seed in North America, a number of seed companies and nurseries were founded in Philadelphia.
The increased availability of these grasses meant they were in plentiful supply
Flora of China
The flora of China is diverse. More than 30,000 plant species are native to China, representing nearly one-eighth of the world's total plant species, including thousands found nowhere else on Earth. China contains a variety of forest types. Both northeast and northwest reaches contain mountains and cold coniferous forests, supporting animal species which include moose and Asiatic black bear, along with some 120 types of birds. Moist conifer forests can have thickets of bamboo as an understorey, replaced by rhododendrons in higher montane stands of juniper and yew. Subtropical forests, which dominate central and southern China, support an astounding 146,000 species of flora. Tropical rainforest and seasonal rainforests, though confined to Yunnan and Hainan Island, contain a quarter of all the plant and animal species found in China; the flora of China has an online database which gives both its taxonomy. Media related to Flora of China at Wikimedia Commons eflora: Flora of China
Ornamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as houseplants, cut flowers and specimen display. The cultivation of ornamental plants is called floriculture, which forms a major branch of horticulture. Ornamental plants are grown for the display of aesthetic features including: flowers, scent, overall foliage texture, fruit and bark, aesthetic form. In some cases, unusual features may be considered to be of interest, such as the prominent thorns of Rosa sericea and cacti. In all cases, their purpose is for the enjoyment of gardeners and the public institutions. Certain trees may be called ornamental trees; this term is used when they are used as part of a garden, park, or landscape setting, for instance for their flowers, their texture, form and shape, other aesthetic characteristics. In some countries trees in'utilitarian' landscape use such as screening, roadside plantings are called amenity trees. Ornamental grasses are grasses grown as ornamental plants.
Many ornamental grasses are true grasses, however several other families of grass-like plants are marketed as ornamental grasses. These include the sedges, rushes and cat-tails. All are monocotyledons with narrow leaves and parallel veins. Most are herbaceous perennials, though many are evergreen and some develop woody tissues. Ornamental grasses are popular in many countries, they bring striking linear form, color and sound to the garden, throughout the year. Ornamental grasses are popular in many colder hardiness zones for their resilience to cold temperatures and aesthetic value throughout fall and winter seasons. For plants to be considered ornamental, they require specific pruning by a gardener. For instance, many plants cultivated for topiary and bonsai would only be considered to be ornamental by virtue of the regular pruning carried out on them by the gardener, they may cease to be ornamental if the work was abandoned. Ornamental plants and trees are distinguished from utilitarian and crop plants, such as those used for agriculture and vegetable crops, for forestry or as fruit trees.
This does not preclude any particular type of plant being grown both for ornamental qualities in the garden, for utilitarian purposes in other settings. Thus lavender is grown as an ornamental plant in gardens, but may be grown as a crop plant for the production of lavender oil; the term ornamental plant is used here in the same sense that it is used in the horticultural trades. The term corresponds to'garden plant', though the latter is much less precise, as any plant may be grown in a garden. Ornamental plants are plants, rather than functional ones. While some plants are both ornamental and functional, people use the term “ornamental plants” to refer to plants which have no value beyond being attractive, although many people feel that this is value enough. Ornamental plants are the keystone of ornamental gardening, they come in a range of shapes and colors suitable to a broad array of climates and gardening needs; some ornamental plants are grown for showy foliage. Their foliage may be deciduous, turning bright orange and yellow before dropping off in the fall, or evergreen, in which case it stays green year-round.
Some ornamental foliage has a striking appearance created by lacy leaves or long needles, while other ornamentals are grown for distinctively colored leaves, such as silvery-gray ground covers and bright red grasses, among many others. Other ornamental plants are cultivated for their blooms. Flowering ornamentals are a key aspect of many gardens, with many flower gardeners preferring to plant a variety of flowers so that the garden is continuously in flower through the spring and summer. Depending on the types of plants being grown, the flowers may be subtle and delicate, or large and showy, with some ornamental plants producing distinctive aromas which paint a palette of scents in addition to colors. Media related to Ornamental plants at Wikimedia Commons
Herbaceous plant
Herbaceous plants are plants that have no persistent woody stem above ground. The term is applied to perennials, but in botany it may refer to annuals or biennials, include both forbs and graminoids. Annual herbaceous plants die at the end of the growing season or when they have flowered and fruited, they grow again from seed. Herbaceous perennial and biennial plants may have stems that die at the end of the growing season, but parts of the plant survive under or close to the ground from season to season. New growth develops from living tissues remaining on or under the ground, including roots, a caudex or various types of underground stems, such as bulbs, stolons and tubers. Examples of herbaceous biennials include carrot and common ragwort. By contrast, non-herbaceous perennial plants are woody plants which have stems above ground that remain alive during the dormant season and grow shoots the next year from the above-ground parts – these include trees and vines; some fast-growing herbaceous plants are pioneers, or early-successional species.
Others form the main vegetation of many stable habitats, occurring for example in the ground layer of forests, or in open habitats such as meadow, salt marsh or desert. Some herbaceous plants can grow rather large, such as the genus Musa; the age of some herbaceous perennial plants can be determined by herbchronology, the analysis of annual growth rings in the secondary root xylem
Weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place". Examples are plants unwanted in human-controlled settings, such as farm fields, gardens and parks. Taxonomically, the term "weed" has no botanical significance, because a plant, a weed in one context is not a weed when growing in a situation where it is in fact wanted, where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed, such as a wild bramble growing among cultivated loganberries. In the same way, volunteer crops are regarded as weeds in a subsequent crop. Many plants that people regard as weeds are intentionally grown in gardens and other cultivated settings, in which case they are sometimes called beneficial weeds; the term weed is applied to any plant that grows or reproduces aggressively, or is invasive outside its native habitat. More broadly "weed" is applied pejoratively to species outside the plant kingdom, species that can survive in diverse environments and reproduce quickly.
Weed control is important in agriculture. Methods include hand cultivation with hoes, powered cultivation with cultivators, smothering with mulch, lethal wilting with high heat, burning, or chemical attack with herbicides. Certain classes of weeds share adaptations to ruderal environments; that is to say: disturbed environments where soil or natural vegetative cover has been damaged or gets damaged, disturbances that give the weeds advantages over desirable crops, pastures, or ornamental plants. The nature of the habitat and its disturbances will affect or determine which types of weed communities become dominant. Examples of such ruderal or pioneer species include plants that are adapted to occurring disturbed environments such as dunes and other windswept areas with shifting soils, alluvial flood plains, river banks and deltas, areas that are burned repeatedly. Since human agricultural practices mimic these natural environments where weedy species have evolved, some weeds are preadapted to grow and proliferate in human-disturbed areas such as agricultural fields, lawns and construction sites.
The weedy nature of these species gives them an advantage over more desirable crop species because they grow and reproduce they have seeds that persist in the soil seed bank for many years, or they may have short lifespans with multiple generations in the same growing season. In contrast, perennial weeds have underground stems that spread under the soil surface or, like ground ivy, have creeping stems that root and spread out over the ground; some plants become dominant when introduced into new environments because the animals in their original environment, that compete with them or feed on them are absent. An example is Klamath weed, that threatened millions of hectares of prime grain and grazing land in North America after it was accidentally introduced, but was reduced to a rare roadside weed within several years after some of its natural enemies were imported during World War II. In locations where predation and mutually competitive relationships are absent, weeds have increased resources available for growth and reproduction.
The weediness of some species that are introduced into new environments may be caused by their production of allelopathic chemicals which indigenous plants are not yet adapted to, a scenario sometimes called the "novel weapons hypothesis". These chemicals may limit the growth of established plants or the germination and growth of seeds and seedlings. Another of the ways in which the ecological role of a plant can make it a weed if it is in itself inoffensive, is if it harbours a pest, dependent on it for survival. A number of native or non-native plants are unwanted in a specific location for a number of reasons. An important one is that they interfere with food and fiber production in agriculture, wherein they must be controlled in order to prevent lost or diminished crop yields. Other important reasons are that they interfere with other cosmetic, decorative, or recreational goals, such as in lawns, landscape architecture, playing fields, golf courses, they can be of concern for environmental reasons whereby introduced species out-compete for resources or space with desired endemic plants.
For all these reasons. In weed ecology some authorities speak of the relationship between "the three Ps": plant, perception; these have been variously defined, but the weed traits listed by H. G. Ba
