WE ARE surrounded on all sides by soil. It is taken for granted by most people. But, since life on this planet could not exist without soil, it is sobering to learn that in just one country of southern Africa many millions of tons of soil are lost each year. And according to Dr. Kai Curry-Lindhal, UNESCO biologist and conservationist, the world soil loss during the past century was an estimated 2,023 million hectares (5,000 million acres)—about one quarter of the earth’s total farmland.
What causes such drastic loss of valuable topsoil so essential for life? Soil erosion.
What Causes Soil Erosion?
Erosion results from denuding the soil of grass or plants by overgrazing (too many cattle in an area) or plowing and leaving bare the topsoil, which is then blown away by wind or washed away by water. The mantle of soil on the earth is relatively thin, no more than 30 cm (12 inches) deep in many places.
Regarding the effects of erosion, the magazine Veldtrust, of August 1975, said: “The tragedy of South Africa has been the appalling rapidity with which its fertility reserves have been depleted and its thin soil covering washed away. In no other country have the disastrous consequences of erosion followed so quickly after its commencement.”
Farming has changed drastically in South Africa, as in most countries. In earlier years farmers would do what is called “subsistence farming”—they were concerned only with providing enough for their private needs. But as people became concentrated in towns the emphasis was on production. This led to what is known as “soil mining,” that is, exploiting the soil for a maximum return. As a result, the soil was overtaxed, causing the erosion problem that has now taken on national proportions. So man’s misuse of the soil over a long period has been the direct cause of this problem.
In Canada, the pulp industry has denuded huge forests. In Australia, the overgrazing by many millions of sheep has caused erosion. The same thing has happened in Iraq. Forage experts say that the pasturage in northern Iraq could support about 250,000 head of sheep, but there are at least a million grazing there. As civilization has spread, so has erosion.
But what does widespread erosion mean in practical terms? Are its effects overstressed, or does it really pose a threat to man’s continued existence?
The Extent of the Damage
Looked at from the point of view of the farmer, soil erosion means poorer crops, which, in turn, results in poorer feed for his animals. Both crops and animals will be more susceptible to disease and parasites, and this will further affect his production. If the situation goes unchecked, the time may come when his farm can no longer provide him with a livelihood.
Erosion also lessens the water supply in an area. Where there is plenty of vegetation, this helps to hold the water until it seeps into the ground; but where the land is exposed, the water tends to run off into the nearest river and carry with it much valuable topsoil. The fine silt gets to the sea, but the heavier silt is deposited along the lower reaches of rivers, gradually raising the riverbeds and resulting in more serious and more frequent floods. In South Africa, vast quantities of silt have been deposited in irrigation dams built by the State at great cost, and these dams could eventually be rendered useless.
The U.S.A. is also grappling with erosion. It is reputed to have nearly 250 million hectares (600 million acres) of agricultural land, but by 1940, 40 million ha (100 million acres) had been lost, most of it in this century.
Italy revealed to a conference held in Stockholm in 1972 that 80 percent of her grazing land in the Apennines and Alps was seriously damaged. Tanzania’s serious erosion problem has resulted in 30 percent of children under five years in the Dar es Salaam district suffering from malnutrition diseases. And Syria, the Congo, Kenya, Chile, India and many other countries face serious consequences as a result of soil erosion.
Erosion also acts like a catalyst in helping the great deserts to spread. In the last 50 years an estimated 650,000 km2 (250,000 square miles) of farming and grazing lands have been swallowed up by the Sahara along its southern edge, sometimes called the “Sahel.” In the Sahel more than 100,000 people have died as a result of drought and famine. Hundreds of thousands of tribesmen have lost their livestock and gone to refugee camps.
The problem is indeed serious and urgent, especially in the poorer countries. As their land becomes infertile, people move into towns and cities and put an extra strain on the food supplies there. The United Nations secretary-general, Kurt Waldheim, warned: “Countries could disappear from the face of the map. We risk destroying whole peoples in the afflicted area.”
These are shocking realities. But virtually all authorities on the subject agree on the cause—man’s unwise use of the land.
However, you may be surprised to learn that the natural process of soil erosion, when not aggravated by man, is actually a friend!
When Soil Erosion Is a Friend
The natural process of erosion by weathering, wind and water is very beneficial, as it breaks down rocks eventually to form soil. Without this process there would be no soil in which plants could grow, for soil consists largely of mineral grains that come from rocks.
Plants play an important role in keeping this erosion process under control. They tend to hold the soil in place and prevent rainwater from carrying the soil away. The plants trap the water so that it gradually seeps into the ground. Plants also help to contribute to the formation of soil, as their roots are constantly prying rocks apart, helping to grind them up into smaller fragments.
Animals also play an important part by helping to preserve the vegetation. This is well illustrated in South Africa, which used to have a large number of wild animals before man killed the majority of them off. Wrote James Clarke, in his book Our Fragile Land (pp. 69, 70):
“Every species had its contribution to make towards maintaining the soil cover, even if it was merely by donating its droppings or carcass to the replenishing process. Hippos played an important mechanical role by habitually walking away from a river in the direction of its flow so that when the river was in flood the rising waters would finger gently outwards—nature’s own irrigation system. Today, in most areas the hippos have been shot out and the banks of the rivers cultivated so that when the floods come they roll up the land and carry it off into the sea. Elephants had the habit of pushing trees into dongas [gullies]—a strange habit, but one with an obvious element of self-preservation in it, for it helped block the dongas and so they filled up, and as the land scar gradually disappeared the veld flourished once more. And elephants also had the habit of pushing over thorn trees so that they littered the veld. But each fallen tree effectively protected islands of grass from desperate grazers in times of drought. These specially protected grass nurseries would often be the only grasses left after a really severe drought and would seed the veld when spring winds and rains came.”
This is all evidence of a wise Creator who designed the earth and life on it in such a balanced way that everything would run smoothly. But man, by upsetting the balance of life designed by the Creator, has reaped the unpleasant results we see around us today. However, recently men have been trying to overcome the problem.
What Is Being Done
In South Africa, Soil Conservation Acts were passed in 1946 and 1969 to help farmers and encourage their cooperation with the State. As a result, many farmers have improved their farming methods, although there is still much to be done.
In many parts of southern Africa dry, windy weather occurs in winter when the soil is barren. To reduce loss of soil by wind, hedges or windbreaks are planted between arable strips to lessen its force. In some cases winter crops or fodder are grown to help keep the soil in place. The addition of lime causes adhesion of soil particles and also prevents or reduces the loss of soil.
Many farmers now practice contour farming—not plowing up and down slopes, but following the same level of terrain in and out of its contours or curves, thus preventing the furrows from acting as eroding water channels after heavy rainfall. Also, planting strips of grass down the slope of the land at suitable places helps the flow of water to spread and prevents erosive dongas. On some farms, watering the crops is not done by irrigation furrows that carry off topsoil but by spraying, or by other mechanical means. Further water control is achieved by constructing many small dams in valleys and on hill slopes; also, by putting rocks and branches in old dongas so that they get filled up and eventually are covered with grass.
Trying to raise too many animals in a certain area (overgrazing) is one of the main causes of destructive soil erosion. Control, not only of the number of animals, but also of their movements is important. Cattle have their own peculiar ways. If a herd has a long walk to water or to the kraal (cattle pen) for the night, they usually do so in single file and form deep tracks that become watercourses in heavy rains. So, where possible, many farmers now just let their cattle spend the night in the veld. They also provide smaller grazing areas with convenient drinking places so as to eliminate footpaths.
Man, too, needs controlling. In South Africa, it is a time-honoured custom to burn the veld in winter (to reduce ticks, pests, and so forth). But this causes a thinner grass coverage, resulting in more erosion. So this is now illegal in South Africa, except by permit.
Countries threatened by “desertification” have taken steps to halt the invading deserts. The people of Saudi Arabia have planted 10 million tamarisk, acacia and eucalyptus trees to save the al-Hasa oasis, near Hofuf, from the encroaching desert. They have also tried spraying the sand with a petrochemical “glue” that binds the grains together and prevents the sand from blowing away. The Libyans have tapped the so-called fossil water locked under the desert and have also made large circular patches of farmland in the Sahara desert with the aid of irrigation techniques developed in America. The Chinese have succeeded in growing new grasslands, vineyards, cotton and other crops in the desert area of Sinkiang.
The Israelis have restored water collection systems built by the ancient Nabateans in the Negev desert, and are using these to water orchards of almond and pistachio trees. Drip irrigation systems are also being used in the Negev, and these systems carry small quantities of water directly to the roots of plants, using computer monitors.
But there are still many setbacks facing those trying to save the environment from irreparable damage. The United Nations in 1977 called for international cooperation “on a scale not seen so far in the history of mankind.” Is such cooperation likely to occur? The meeting in Nairobi was marred by political ill feeling and disunity. One observer said: “So much political sniping and hollow hyperbole go on in open and closed sessions that you begin to feel that one of the greatest deserts is the human mind.”
Legislation by governments is not enough because it cannot change the selfish desires of men. To solve the problem of erosion, as well as the host of others facing mankind, it needs a completely new system of things, a new approach to problems and progress based on the great law: “You must love your neighbor as yourself.”Only the great Maker of this beautiful planet can accomplish such a change. Only he can restore the perfect balance of natural forces as at the beginning.
Friday, May 30, 2008
Pollen Menace or Miracle?
Ah-choo! That sound, combined with watery, itchy eyes and a drippy, irritated nose, heralds the arrival of spring for millions of people. Their allergy usually results from an atmosphere laden with pollen. The BMJ (formerly British Medical Journal) estimates that 1 in 6 people in the industrialized world suffers from seasonal pollen allergies, also called hay fever. That number is hardly surprising considering the staggering amount of pollen that plants release into the air.
Scientists estimate that the spruce forests in just the southern third of Sweden release about 75,000 tons of pollen each year. A single ragweed plant, the bane of North American hay-fever sufferers, can produce a million grains of pollen a day. Carried by the breeze, ragweed pollen has been found 2 miles [3 km] above the earth and up to 400 miles [600 km] out to sea.
But why does pollen trigger an allergic reaction in some people? Before we consider that question, let us take a close look at pollen and see the amazing design found in these minute grains.
Tiny Grains of Life
Pollen, says The Encyclopædia Britannica, is “formed in the anther, or male apparatus, in seed-bearing plants and transported by various means (wind, water, insects, etc.) to the pistil, or female structure, where fertilization occurs.”
In flowering plants, pollen grains are made up of three distinct parts—a nucleus of sperm cells and two layers that make up the wall or shell of the grain. The tough outer layer is highly resistant to disintegration and able to withstand strong acids, alkalies, and even intense heat. Nevertheless, with few exceptions, pollen is viable for only several days or weeks. The tough shell, though, may last for thousands of years without decaying. Hence, pollen grains can be found in abundance in the earth’s soil. In fact, scientists have learned much about the earth’s botanical history by studying pollen found in soil samples taken from various depths.
That history can also be quite accurate, thanks to the distinctive designs found on the outer shell of pollen grains. Depending on the type of pollen, the shell may be smooth, wrinkled, patterned, or covered with spines and knobs. “Thus, for purposes of identification, the pollen of each species is as reliable as a human fingerprint,” says professor of anthropology Vaughn M. Bryant, Jr.
How Plants Pollinate
Once a pollen grain comes in contact with the stigma, a part of the pistil in female plants, a chemical reaction causes the pollen grain to swell and to grow a tube that reaches down to the ovule. Sperm cells from inside the pollen grain then travel down the tube to the ovule, causing a fertilized seed to form. When the seed is mature, it simply needs to settle in the right environment in order to germinate.
While some seed-bearing plants grow as either male or female, most produce both pollen and ovules. Some plants self-pollinate; others cross-pollinate by transferring pollen to other plants of the same species or of a closely related one. Those that cross-pollinate “often avoid self-pollination by shedding their pollen either before or after the stigmas on the same plant are receptive to it,” says Britannica. Others have the chemical wherewithal to detect the difference between their own pollen and that of another plant of the same kind. When they detect their own pollen, they inactivate it, often by blocking the growth of the pollen tube.
In an area where there is a variety of vegetation, the air may be a veritable cocktail of pollens. How do plants sift out the pollen they require? Some employ complex principles of aerodynamics. Consider pine trees, for example.
Harvesting the Wind
Male pinecones grow in clusters and, when mature, release clouds of pollen to the wind. Scientists have discovered that female pinecones, in cooperation with the pine needles surrounding them, channel airflow in such a way that airborne pollen swirls and falls toward the reproductive surfaces of the cones. In receptive females these surfaces become exposed when the scales open slightly, separating from one another.
Researcher Karl J. Niklas conducted extensive tests on the aeronautical wizardry of pinecones. In the magazine Scientific American, he wrote: “Our studies reveal that the unique shape of the cone produced by each plant species results in idiosyncratic [distinctive] modifications of the airflow patterns . . . Similarly, each type of pollen has a distinctive size, shape and density, causing the pollen to interact with the turbulence in a unique way.” How effective are these techniques? Says Niklas: “Most of the cones we studied filtered their ‘own’ pollen from the air but not that of other species.”
Of course, not all plants pollinate by harnessing the wind—much to the relief of allergy sufferers! Many make use of animals.
Seduced by Nectar
Plants that are pollinated by birds, small mammals, and insects usually employ things like hooks, spines, or sticky threads to attach pollen to the body of the foraging pollinator. A hairy bumblebee, for example, may find itself hauling off some 15,000 pollen grains in a single load!
Bees, in fact, are the preeminent pollinators of flowering plants. In return, plants reward bees by giving them both sweet nectar and pollen to eat, the latter providing proteins, vitamins, minerals, and fats. In an extraordinary act of cooperation, bees may visit over 100 flowers on a single trip, but they will collect pollen, nectar, or both from just one species until they have gathered enough or until supplies run out. This remarkable, instinctive behavior helps to ensure efficient pollination.
Fooled by Flowers
Instead of offering sweet treats, some plants rely on elaborate deceptions to coax insects to pollinate them. Consider the hammer orchid, which grows in Western Australia. The hammer orchid’s flower has a lower lip that, even to the human eye, almost perfectly resembles the plump, wingless female thynnid wasp. The flower even emits a chemical copy of the sex pheromone, or sex attractant, of the real female wasp! Poised at the end of an arm just above this alluring decoy are sticky bags filled with pollen.
A male thynnid wasp, lured by the scent of the imitation pheromone, will grab the decoy and try to fly off with “her” in his grasp. As he takes off, however, his momentum flips him and his intended up and over, right into the sticky pollen sacks. After realizing his mistake, he releases the decoy—which is conveniently attached to a hinge, allowing it to fall back into place—and flies off, only to be fooled again by another hammer orchid. This time, however, he pollinates the orchid with the pollen he picked up on his previous encounter.
But if female thynnid wasps are active, males will invariably choose one of them, not the impostor. Conveniently, the orchid blooms several weeks before female wasps emerge from their underground pupae, giving the flower a temporary advantage.
Why the Allergies?
Why are some people allergic to pollen? When tiny pollen grains lodge in the nose, they get trapped by a layer of sticky mucous. From there they move to the throat, where they are swallowed or coughed out, usually without any ill effects. Sometimes, though, pollen excites the immune system.
The problem lies in pollen protein. For some reason the immune system of an allergy sufferer views the protein of certain pollens as a threat. The body reacts by setting off a chain reaction that causes mast cells, which are found in the body’s tissues, to release histamine in inordinate amounts. Histamine causes blood vessels to dilate and become more permeable, so that they leak fluids that are rich in immune cells. Under normal circumstances, these immune cells migrate to the site of injury or infection, where they help to rid the body of harmful invaders. For allergy sufferers, however, pollen triggers a false alarm, which translates into irritated, dripping nostrils, swollen tissue, and watery eyes.
Researchers believe that people inherit the tendency to be allergic from their parents, although the tendency may not relate to a specific allergen. Pollution could also be a sensitizing factor. “In Japan a direct relation was found between sensitivity to pollen and proximity to areas with high levels of diesel exhaust particles in ambient air,” said the BMJ. “Animal studies suggest that these particles increase allergic sensitisation.”
Happily, for many sufferers, antihistamines can ease their symptoms. As the name suggests, these drugs oppose the action of histamine. Despite pollen’s irritating effects, however, one cannot help but be deeply impressed by the ingenuity evident in both the design and the dispersal of these tiny particles of life. Without them, planet Earth would be a barren place indeed.
Scientists estimate that the spruce forests in just the southern third of Sweden release about 75,000 tons of pollen each year. A single ragweed plant, the bane of North American hay-fever sufferers, can produce a million grains of pollen a day. Carried by the breeze, ragweed pollen has been found 2 miles [3 km] above the earth and up to 400 miles [600 km] out to sea.
But why does pollen trigger an allergic reaction in some people? Before we consider that question, let us take a close look at pollen and see the amazing design found in these minute grains.
Tiny Grains of Life
Pollen, says The Encyclopædia Britannica, is “formed in the anther, or male apparatus, in seed-bearing plants and transported by various means (wind, water, insects, etc.) to the pistil, or female structure, where fertilization occurs.”
In flowering plants, pollen grains are made up of three distinct parts—a nucleus of sperm cells and two layers that make up the wall or shell of the grain. The tough outer layer is highly resistant to disintegration and able to withstand strong acids, alkalies, and even intense heat. Nevertheless, with few exceptions, pollen is viable for only several days or weeks. The tough shell, though, may last for thousands of years without decaying. Hence, pollen grains can be found in abundance in the earth’s soil. In fact, scientists have learned much about the earth’s botanical history by studying pollen found in soil samples taken from various depths.
That history can also be quite accurate, thanks to the distinctive designs found on the outer shell of pollen grains. Depending on the type of pollen, the shell may be smooth, wrinkled, patterned, or covered with spines and knobs. “Thus, for purposes of identification, the pollen of each species is as reliable as a human fingerprint,” says professor of anthropology Vaughn M. Bryant, Jr.
How Plants Pollinate
Once a pollen grain comes in contact with the stigma, a part of the pistil in female plants, a chemical reaction causes the pollen grain to swell and to grow a tube that reaches down to the ovule. Sperm cells from inside the pollen grain then travel down the tube to the ovule, causing a fertilized seed to form. When the seed is mature, it simply needs to settle in the right environment in order to germinate.
While some seed-bearing plants grow as either male or female, most produce both pollen and ovules. Some plants self-pollinate; others cross-pollinate by transferring pollen to other plants of the same species or of a closely related one. Those that cross-pollinate “often avoid self-pollination by shedding their pollen either before or after the stigmas on the same plant are receptive to it,” says Britannica. Others have the chemical wherewithal to detect the difference between their own pollen and that of another plant of the same kind. When they detect their own pollen, they inactivate it, often by blocking the growth of the pollen tube.
In an area where there is a variety of vegetation, the air may be a veritable cocktail of pollens. How do plants sift out the pollen they require? Some employ complex principles of aerodynamics. Consider pine trees, for example.
Harvesting the Wind
Male pinecones grow in clusters and, when mature, release clouds of pollen to the wind. Scientists have discovered that female pinecones, in cooperation with the pine needles surrounding them, channel airflow in such a way that airborne pollen swirls and falls toward the reproductive surfaces of the cones. In receptive females these surfaces become exposed when the scales open slightly, separating from one another.
Researcher Karl J. Niklas conducted extensive tests on the aeronautical wizardry of pinecones. In the magazine Scientific American, he wrote: “Our studies reveal that the unique shape of the cone produced by each plant species results in idiosyncratic [distinctive] modifications of the airflow patterns . . . Similarly, each type of pollen has a distinctive size, shape and density, causing the pollen to interact with the turbulence in a unique way.” How effective are these techniques? Says Niklas: “Most of the cones we studied filtered their ‘own’ pollen from the air but not that of other species.”
Of course, not all plants pollinate by harnessing the wind—much to the relief of allergy sufferers! Many make use of animals.
Seduced by Nectar
Plants that are pollinated by birds, small mammals, and insects usually employ things like hooks, spines, or sticky threads to attach pollen to the body of the foraging pollinator. A hairy bumblebee, for example, may find itself hauling off some 15,000 pollen grains in a single load!
Bees, in fact, are the preeminent pollinators of flowering plants. In return, plants reward bees by giving them both sweet nectar and pollen to eat, the latter providing proteins, vitamins, minerals, and fats. In an extraordinary act of cooperation, bees may visit over 100 flowers on a single trip, but they will collect pollen, nectar, or both from just one species until they have gathered enough or until supplies run out. This remarkable, instinctive behavior helps to ensure efficient pollination.
Fooled by Flowers
Instead of offering sweet treats, some plants rely on elaborate deceptions to coax insects to pollinate them. Consider the hammer orchid, which grows in Western Australia. The hammer orchid’s flower has a lower lip that, even to the human eye, almost perfectly resembles the plump, wingless female thynnid wasp. The flower even emits a chemical copy of the sex pheromone, or sex attractant, of the real female wasp! Poised at the end of an arm just above this alluring decoy are sticky bags filled with pollen.
A male thynnid wasp, lured by the scent of the imitation pheromone, will grab the decoy and try to fly off with “her” in his grasp. As he takes off, however, his momentum flips him and his intended up and over, right into the sticky pollen sacks. After realizing his mistake, he releases the decoy—which is conveniently attached to a hinge, allowing it to fall back into place—and flies off, only to be fooled again by another hammer orchid. This time, however, he pollinates the orchid with the pollen he picked up on his previous encounter.
But if female thynnid wasps are active, males will invariably choose one of them, not the impostor. Conveniently, the orchid blooms several weeks before female wasps emerge from their underground pupae, giving the flower a temporary advantage.
Why the Allergies?
Why are some people allergic to pollen? When tiny pollen grains lodge in the nose, they get trapped by a layer of sticky mucous. From there they move to the throat, where they are swallowed or coughed out, usually without any ill effects. Sometimes, though, pollen excites the immune system.
The problem lies in pollen protein. For some reason the immune system of an allergy sufferer views the protein of certain pollens as a threat. The body reacts by setting off a chain reaction that causes mast cells, which are found in the body’s tissues, to release histamine in inordinate amounts. Histamine causes blood vessels to dilate and become more permeable, so that they leak fluids that are rich in immune cells. Under normal circumstances, these immune cells migrate to the site of injury or infection, where they help to rid the body of harmful invaders. For allergy sufferers, however, pollen triggers a false alarm, which translates into irritated, dripping nostrils, swollen tissue, and watery eyes.
Researchers believe that people inherit the tendency to be allergic from their parents, although the tendency may not relate to a specific allergen. Pollution could also be a sensitizing factor. “In Japan a direct relation was found between sensitivity to pollen and proximity to areas with high levels of diesel exhaust particles in ambient air,” said the BMJ. “Animal studies suggest that these particles increase allergic sensitisation.”
Happily, for many sufferers, antihistamines can ease their symptoms. As the name suggests, these drugs oppose the action of histamine. Despite pollen’s irritating effects, however, one cannot help but be deeply impressed by the ingenuity evident in both the design and the dispersal of these tiny particles of life. Without them, planet Earth would be a barren place indeed.
Are They Wildflowers or Weeds?
Wildflowers are fascinating. Pause and examine their intricately shaped blossoms. Look at their diversity of gorgeous colors. Smell their delightful fragrance. And how enticing it is to reach out and touch their soft, delicate petals! Such regal elegance excites our senses. Even our emotions are stirred by such splendor. Truly, wildflowers beautifully complement our environment. They add a unique dimension to our enjoyment of life. For this we are indebted to their Creator and Designer!
While we admire flower blossoms for their bold colors, shapes, and scents, their main function is to make seeds for the vital process of reproduction. To this end, their blooms are designed to attract insects, birds, and even bats for pollination. Songbirds and butterflies especially seek out wildflowers. “They’re a food source for these flying creatures, while cultivated flowers are not,” says horticulturist and author Jim Wilson. It is of interest that according to The World Book Encyclopedia, “originally, all flowers were wild flowers.”
There are many thousands of flowering plants earth wide. So, then, how can a wildflower be identified? What is a wildflower? In very simple terms, a wildflower is any flowering plant that grows without human intervention. In North America alone, more than 10,000 are identified as wildflowers. “While the term refers in general to soft-stemmed plants with showy blooms, wildflower books also include plants with woody stems. These inconsistencies make it virtually impossible to arrive at an all-encompassing definition for every type of plant we call a wildflower,” says naturalist Michael Runtz, author of Beauty and the Beasts—The Hidden World of Wildflowers.
Seeds are great travelers. Some are capable of very long voyages by wind or water. Most, though, have natural limitations because they are designed for specific areas. Winds can carry dust-fine seeds for miles. However, seeds with parachutelike attachments, such as the dandelion, may travel only a fraction of a mile.
It may surprise you to know that if you live in North America, many wildflowers now native to your area have been introduced from different lands. The advent of oceangoing ships and the opening up of new territories spread a host of plants and seeds from their parent lands. Many such plants originated in Europe or Asia. Some were “invited” to come, and others arrived as “stowaways.” In fact, many plants that now decorate the North American landscape originally “came as weeds in agricultural crop seeds; others in cereals and grains; in packing materials such as straw and hay; in ship’s ballast . . . Others were brought as herbs for flavorings, dyes, scents, and medicinal remedies,” says the book Wildflowers Across America. Why, though, are these and countless other flowering plants sometimes called weeds?
When a Wildflower Becomes a Weed
Generally speaking, any plant growing profusely where you do not want it to can be termed a weed, whether it shows up in your lawn, in your garden, or among your crops. “Many plants designated as weeds could not survive . . . if these artificial habitats did not exist,” states the reference book Weeds of Canada. It adds: “We are largely responsible for creating a suitable environment for the growth of the plants that we are most anxious to eliminate.” Some introduced wildflowers invade the habitat of other less-aggressive, naturally occurring plants and radically change the environment. In this way an introduced plant can go beyond becoming a naturalized wildflower and become an invasive weed.
If you have tried to cultivate even the smallest of garden plots, you will understand what is meant by an invasion of uninvited plants. Open ground is susceptible to rapid erosion by wind and water. At any given time, there are literally millions of dormant seeds from a wide variety of plants scattered over the top inch or so of the ground. When an area is open, weeds are programmed to fill in these areas quickly and hold the soil. While this process may cause an ongoing duel in an open garden, understanding it helps you to be aware of the respective roles of both weeds and wildflowers.
Enjoy This Fascinating Part of Creation
You cannot help but admire the unassisted splendor of wooded slopes carpeted with the spring blooms of white trilliums or the sky-blue chicory blossoms that flower in the morning and follow the sun, folding up by noon on a bright day. These merely signal the beginning of a procession of natural beauty that continues through the seasons, year after year, vying for your attention. The appearance of some, such as the tawny daylily, is very brief. Others, the black-eyed Susan for one, can be seen blooming in sunny fields or along roadsides from late spring through summer.
Indeed, the world of wildflowers is a fascinating part of creation. When some show up in your lawn or garden or you notice them on the roadside or in the woods, take the time to admire their intricate shapes, gorgeous colors, and delightful fragrances. Recognize them for what they are—a gift from their Designer, our generous Creator.
The common dandelion was once a complete stranger to all of North America. Now most of the world knows the plant. Some authorities claim it originated in Asia Minor. European settlers in the Americas, accustomed to using it as a food source, took it with them for their new gardens. The dandelion root has been used in many patent medicines, while its young leaves have been served in salads.
Oxeye daisies are among the most common roadside flowers. Their origin is Europe. For the most part, they are a cheerful addition to the scenery. Each blossom is really a bouquet of yellow and white flowers. The center disk is composed of hundreds of tiny, fertile, golden florets encircled by 20 to 30 white rays, or petals, that are sterile flowers—landing pads for insects.
The tawny daylily, it is believed, came from Asia and was then taken to England and eventually North America. While each stem puts forth many flowers, each bloom lasts only one day. They open in the morning and close forever by the end of the day.
The tall buttercup was also transported from Europe to North America. There, it is generally found in moist fields and along roadsides. At times it grows to six or more feet [2 m] in height. Few people realize, though, that it can be dangerous. Nearly all species of this flower are acrid in varying degrees. For centuries some buttercups have been known as blister plants. Anne Pratt, a 19th-century British writer, stated: “Instances are common in which the wanderer has lain down to sleep with a handful of these flowers beside him, and has awakened to find the skin of his cheek pained and irritated to a high degree by the acrid blossoms’ having lain near it.”
While we admire flower blossoms for their bold colors, shapes, and scents, their main function is to make seeds for the vital process of reproduction. To this end, their blooms are designed to attract insects, birds, and even bats for pollination. Songbirds and butterflies especially seek out wildflowers. “They’re a food source for these flying creatures, while cultivated flowers are not,” says horticulturist and author Jim Wilson. It is of interest that according to The World Book Encyclopedia, “originally, all flowers were wild flowers.”
There are many thousands of flowering plants earth wide. So, then, how can a wildflower be identified? What is a wildflower? In very simple terms, a wildflower is any flowering plant that grows without human intervention. In North America alone, more than 10,000 are identified as wildflowers. “While the term refers in general to soft-stemmed plants with showy blooms, wildflower books also include plants with woody stems. These inconsistencies make it virtually impossible to arrive at an all-encompassing definition for every type of plant we call a wildflower,” says naturalist Michael Runtz, author of Beauty and the Beasts—The Hidden World of Wildflowers.
Seeds are great travelers. Some are capable of very long voyages by wind or water. Most, though, have natural limitations because they are designed for specific areas. Winds can carry dust-fine seeds for miles. However, seeds with parachutelike attachments, such as the dandelion, may travel only a fraction of a mile.
It may surprise you to know that if you live in North America, many wildflowers now native to your area have been introduced from different lands. The advent of oceangoing ships and the opening up of new territories spread a host of plants and seeds from their parent lands. Many such plants originated in Europe or Asia. Some were “invited” to come, and others arrived as “stowaways.” In fact, many plants that now decorate the North American landscape originally “came as weeds in agricultural crop seeds; others in cereals and grains; in packing materials such as straw and hay; in ship’s ballast . . . Others were brought as herbs for flavorings, dyes, scents, and medicinal remedies,” says the book Wildflowers Across America. Why, though, are these and countless other flowering plants sometimes called weeds?
When a Wildflower Becomes a Weed
Generally speaking, any plant growing profusely where you do not want it to can be termed a weed, whether it shows up in your lawn, in your garden, or among your crops. “Many plants designated as weeds could not survive . . . if these artificial habitats did not exist,” states the reference book Weeds of Canada. It adds: “We are largely responsible for creating a suitable environment for the growth of the plants that we are most anxious to eliminate.” Some introduced wildflowers invade the habitat of other less-aggressive, naturally occurring plants and radically change the environment. In this way an introduced plant can go beyond becoming a naturalized wildflower and become an invasive weed.
If you have tried to cultivate even the smallest of garden plots, you will understand what is meant by an invasion of uninvited plants. Open ground is susceptible to rapid erosion by wind and water. At any given time, there are literally millions of dormant seeds from a wide variety of plants scattered over the top inch or so of the ground. When an area is open, weeds are programmed to fill in these areas quickly and hold the soil. While this process may cause an ongoing duel in an open garden, understanding it helps you to be aware of the respective roles of both weeds and wildflowers.
Enjoy This Fascinating Part of Creation
You cannot help but admire the unassisted splendor of wooded slopes carpeted with the spring blooms of white trilliums or the sky-blue chicory blossoms that flower in the morning and follow the sun, folding up by noon on a bright day. These merely signal the beginning of a procession of natural beauty that continues through the seasons, year after year, vying for your attention. The appearance of some, such as the tawny daylily, is very brief. Others, the black-eyed Susan for one, can be seen blooming in sunny fields or along roadsides from late spring through summer.
Indeed, the world of wildflowers is a fascinating part of creation. When some show up in your lawn or garden or you notice them on the roadside or in the woods, take the time to admire their intricate shapes, gorgeous colors, and delightful fragrances. Recognize them for what they are—a gift from their Designer, our generous Creator.
The common dandelion was once a complete stranger to all of North America. Now most of the world knows the plant. Some authorities claim it originated in Asia Minor. European settlers in the Americas, accustomed to using it as a food source, took it with them for their new gardens. The dandelion root has been used in many patent medicines, while its young leaves have been served in salads.
Oxeye daisies are among the most common roadside flowers. Their origin is Europe. For the most part, they are a cheerful addition to the scenery. Each blossom is really a bouquet of yellow and white flowers. The center disk is composed of hundreds of tiny, fertile, golden florets encircled by 20 to 30 white rays, or petals, that are sterile flowers—landing pads for insects.
The tawny daylily, it is believed, came from Asia and was then taken to England and eventually North America. While each stem puts forth many flowers, each bloom lasts only one day. They open in the morning and close forever by the end of the day.
The tall buttercup was also transported from Europe to North America. There, it is generally found in moist fields and along roadsides. At times it grows to six or more feet [2 m] in height. Few people realize, though, that it can be dangerous. Nearly all species of this flower are acrid in varying degrees. For centuries some buttercups have been known as blister plants. Anne Pratt, a 19th-century British writer, stated: “Instances are common in which the wanderer has lain down to sleep with a handful of these flowers beside him, and has awakened to find the skin of his cheek pained and irritated to a high degree by the acrid blossoms’ having lain near it.”
Beautiful and Delicious!
Beautiful and Delicious!
VISIT a flower garden, and your senses are immediately rewarded. You enjoy the sight of the flowers’ colors, their shapes, and their intricate designs. You smell their fragrances. You feel the varied textures of their petals. But what about your sense of taste? Can you also find pleasure in the taste of flowers? In some countries, people have enjoyed the flavor of edible flowers for centuries. If you have one of the following available in your flower or vegetable garden, maybe you too would enjoy the experience.
The Romantic Rose
Around the world, the rose (genus Rosa) is probably the best-known and the most appreciated flower. Besides the primary species, there are thousands of man-made hybrids. Since flavor is affected by such factors as soil and temperature, it is advisable to taste a petal of the rose or any other flower before you decide to use the flower as food. You will probably notice that the base of the petal is somewhat bitter. If it is, cut out that part, or if you are serving the complete flower, eat only the outer part.
The list of dishes that can be enriched by roses is practically endless. Try them in salads, maybe with some mild cheese and chopped nuts. Use smashed petals of red roses as an extra ingredient in your favorite sauce to add flavor and color. And what about giving your spaghetti the final touch of rose petals cut into strips? Roses will also enhance the flavor of ice cream and your favorite beverage.
The Squash Blossom
Records of the squash blossom (Cucurbita pepo) being used for food in the Americas date back to the 16th century, and it seems that Native Americans used to eat only male flowers (those grown on long and slender stems) in order to allow female flowers (those with a very small squash behind them) to reproduce. Before cooking the flowers, remove the outside prickly leaves. Pistils can be taken off or left on. In entrées and soups, the mild flavor of squash blossoms goes well with olive oil, tender corn, and the squash itself. For a stronger flavor, sauté the blossoms with some onion, garlic, herbs, and spices of your choice. You can also stuff the flowers with a mixture of cheese, onion, and herbs. Then close the end, and dip the blossoms in an egg mixture of whisked egg whites to which yolks have been added. Finally, dip the blossoms in bread crumbs, deep-fry them, and enjoy their unique flavor!
The Colorful Garden Pansy
Bicolored or tricolored garden pansies (Viola wittrockiana) have characteristic dark spots on the petals, which give them an unusual appearance. According to the Encyclopædia Britannica, the garden pansy is usually thought to be a cultivated form of the wild pansy, or Johnny-jump-up (Viola tricolor), colored purple, white, and yellow. This wildflower is also edible, but according to the book Edible Flowers—From Garden to Palate, it “may be toxic in large amounts.” It greatly enhances the flavor and appearance of vegetable and fruit salads. Use the entire flower, adding it right before serving and after adding any vinaigrette. You can also serve it on your favorite soup.
A third edible flower of the Viola genus is the garden violet, or English violet (Viola odorata), which goes wonderfully with desserts and beverages. (See the box “Sweet Flowers for Beverages.”) No other flowers of the Viola genus are considered edible.
The Vivacious Daylily
The long, thin, abundant leaves at the base of the daylily (genus Hemerocallis) are characteristic of this plant. Its short-lived flower must not be confused with other flowers of the same family, Liliaceae. Daylilies, whose colors range from yellow to red, have long been used in the kitchen. This flower, lightly cooked, can be served as a vegetable. Another possibility is to combine its petals with ingredients of your choice to make a light paste and then fry it. Garnish it with an entire flower.
Some Other Edibles
The yucca flower (genus Yucca), which grows especially in arid or semiarid climates, is rich in vitamins and calcium. Eat only the petals; you may have to give them a light boil to take away any bitterness. Lemon blossoms (Citrus limon), orange blossoms (Citrus sinensis), and the mint flower (genus Mentha) are excellent additions to beverages, salads, and desserts.
Without a doubt, flowers are a gift to our senses and an important ingredient in our enjoyment of life. Truly they give us additional reasons to thank our loving Creator.
VISIT a flower garden, and your senses are immediately rewarded. You enjoy the sight of the flowers’ colors, their shapes, and their intricate designs. You smell their fragrances. You feel the varied textures of their petals. But what about your sense of taste? Can you also find pleasure in the taste of flowers? In some countries, people have enjoyed the flavor of edible flowers for centuries. If you have one of the following available in your flower or vegetable garden, maybe you too would enjoy the experience.
The Romantic Rose
Around the world, the rose (genus Rosa) is probably the best-known and the most appreciated flower. Besides the primary species, there are thousands of man-made hybrids. Since flavor is affected by such factors as soil and temperature, it is advisable to taste a petal of the rose or any other flower before you decide to use the flower as food. You will probably notice that the base of the petal is somewhat bitter. If it is, cut out that part, or if you are serving the complete flower, eat only the outer part.
The list of dishes that can be enriched by roses is practically endless. Try them in salads, maybe with some mild cheese and chopped nuts. Use smashed petals of red roses as an extra ingredient in your favorite sauce to add flavor and color. And what about giving your spaghetti the final touch of rose petals cut into strips? Roses will also enhance the flavor of ice cream and your favorite beverage.
The Squash Blossom
Records of the squash blossom (Cucurbita pepo) being used for food in the Americas date back to the 16th century, and it seems that Native Americans used to eat only male flowers (those grown on long and slender stems) in order to allow female flowers (those with a very small squash behind them) to reproduce. Before cooking the flowers, remove the outside prickly leaves. Pistils can be taken off or left on. In entrées and soups, the mild flavor of squash blossoms goes well with olive oil, tender corn, and the squash itself. For a stronger flavor, sauté the blossoms with some onion, garlic, herbs, and spices of your choice. You can also stuff the flowers with a mixture of cheese, onion, and herbs. Then close the end, and dip the blossoms in an egg mixture of whisked egg whites to which yolks have been added. Finally, dip the blossoms in bread crumbs, deep-fry them, and enjoy their unique flavor!
The Colorful Garden Pansy
Bicolored or tricolored garden pansies (Viola wittrockiana) have characteristic dark spots on the petals, which give them an unusual appearance. According to the Encyclopædia Britannica, the garden pansy is usually thought to be a cultivated form of the wild pansy, or Johnny-jump-up (Viola tricolor), colored purple, white, and yellow. This wildflower is also edible, but according to the book Edible Flowers—From Garden to Palate, it “may be toxic in large amounts.” It greatly enhances the flavor and appearance of vegetable and fruit salads. Use the entire flower, adding it right before serving and after adding any vinaigrette. You can also serve it on your favorite soup.
A third edible flower of the Viola genus is the garden violet, or English violet (Viola odorata), which goes wonderfully with desserts and beverages. (See the box “Sweet Flowers for Beverages.”) No other flowers of the Viola genus are considered edible.
The Vivacious Daylily
The long, thin, abundant leaves at the base of the daylily (genus Hemerocallis) are characteristic of this plant. Its short-lived flower must not be confused with other flowers of the same family, Liliaceae. Daylilies, whose colors range from yellow to red, have long been used in the kitchen. This flower, lightly cooked, can be served as a vegetable. Another possibility is to combine its petals with ingredients of your choice to make a light paste and then fry it. Garnish it with an entire flower.
Some Other Edibles
The yucca flower (genus Yucca), which grows especially in arid or semiarid climates, is rich in vitamins and calcium. Eat only the petals; you may have to give them a light boil to take away any bitterness. Lemon blossoms (Citrus limon), orange blossoms (Citrus sinensis), and the mint flower (genus Mentha) are excellent additions to beverages, salads, and desserts.
Without a doubt, flowers are a gift to our senses and an important ingredient in our enjoyment of life. Truly they give us additional reasons to thank our loving Creator.
Wednesday, March 12, 2008
Flowers Wallpaper
Peony
The peony or paeony is the only genus in the flowering plant family Paeoniaceae. They are native to Asia, southern Europe and western North America.
Sea Tulips
Sea tulips are sessile ascidians that live in coastal waters at depths of up to 80 m. Like all ascidians, sea tulips are filter feeders. Their common name comes from their appearance - that of a knobbly 'bulb' or flower attached to a long stalk. Sea Tulips come a variety of colours, including white, pink, yellow, orange, and purple. The colouration of sea tulips depends upon their association with a symbiotic sponge that covers their surface.
Plumeria
Plumeria is a small genus of 7-8 species native to tropical and subtropical Americas. The genus consists of mainly deciduous shrubs and trees. P. rubra (Common Frangipani, Red Frangipani), native to Mexico, Central America, and Venezuela, produces flowers ranging from yellow to pink depending on form or cultivar.
Rose
A rose is a flowering shrub of the genus Rosa, and the flower of this shrub.There are more than a hundred species of wild roses, all from the northern hemisphere and mostly from temperate regions. The species form a group of generally prickly shrubs or climbers, and sometimes trailing plants, reaching 2–5 metres tall, occasionally reaching as high as 20 metres by climbing over other plants.
Lily
Lily is an English singer-songwriter best known for songs such as "Smile" and "LDN". She is the daughter of actor/musician Keith Allen and film producer Alison Owen. Allen also hosts her own BBC Three talk show Lily Allen and Friends.
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