Ragweed Traditional Cache

Ragweed is the baddy for us hay fever sufferers. I didn't know what it looked like. Now I do. It's in front of the cache and across the road as well. No need to touch it. This is a P&G

Ragweed

Ragweeds are flowering plants in the genus Ambrosia in the aster family, Asteraceae. They are distributed in the tropical and subtropical regions of the New World, especially North America,  where the origin and center of diverstity of the genus are in the southwestern United States and northwestern Mexico. Several species have been introduced to the Old World and some have naturalized.

Other common names include bursages and burrobrushes. The genus name is from the Greek ambosia, the "food of the gods".

Ragweed pollen is notorious for causing allergic reactions in humans, specifically allergenic rhinitis. Up to half of all cases of pollen-related allergic rhinitis in North America are caused by ragweeds

Description and ecology

Ragweeds are annual and perennial herbs and shrubs. Species may grow just a few centimeters tall or well exceed four meters in height. The stems are erect, decumbent or prostrate, and many grow from rhizomes. The leaves may be arranged alternately, oppositely, or both. The leaf blades come in many shapes, sometimes divided pinnately or palmately into lobes. The edges are smooth or toothed. Some are hairy, and most are glandular.

Ragweeds are monoecious, most producing inflorescences that contain both staminate and pistillate flowers. Inflorescences are often in the form of a spike or raceme made up mostly of staminate flowers with some pistillate clusters around the base. Staminate flower heads have stamens surrounded by whitish or purplish florets. Pistillate flower heads have fruit-yielding ovules surrounded by many phyllaries and fewer, smaller florets. The pistillate flowers are wind pollinated, and the fruits develop. They are burs, sometimes adorned with knobs, wings, or spines.

Many Ambrosia species occur in desert and semi-desert areas, and many are rudder species that grow in disturbed habitat types.

Allergy

Ragweed pollen is a common allergen. A single plant may produce about a billion grains of pollen per season, and the pollen is transported on the wind. It causes about half of all cases of pollen-associated allergic rhinitis in North America, where ragweeds are most abundant and diverse. Common culprits are common ragweed (A. artemisiifolia) and great ragweed (A. trifida).

Ragweed pollen can remain airborne for days and travel great distances, affecting people hundreds of miles away. It can even be carried 300 to 400 miles (640 km) out to sea. Ragweeds native to the Americas have been introduced to Europe starting in the nineteenth century and especially during World War I, and have spread rapidly there since the 1950s. Eastern Europe, particularly Hungary, has been badly affected by ragweed since the early 1990s, when the dismantling of Communist collective agriculture led to large-scale abandonment of agricultural land, and new building projects also resulted in disturbed, un-landscaped acreage.

The major allergenic compound in the pollen has been identified as Amb a 1, a 38 kDa nonglycosylated protein composed of two subunits. It also contains other allergenic components, such as profilin and calcium-binding proteins.

Ragweed allergy sufferers may show signs of oral allergy syndrome, a food allergy classified by a cluster of allergic reactions in the. Foods commonly involved include beans, celery, cumin, hazelnuts, kiwifruit, parsley, potatoes, bananas, melons, cucumbers,and zucchini. Because cooking usually denatures the proteins that cause the reaction, the foods are more allergenic when eaten raw; exceptions are celery and nuts, which may not be safe even when cooked. Signs of reaction can include itching, burning, and swelling of the mouth and throat, runny eyes and nose, hives, and, less commonly, vomiting, diarrhea, asthma, and anaphylaxis. These symptoms are due to the abnormal increase of IgE antibodies which attach to a type of immune cell called mast cells. When the ragweed antigen then attaches to these antibodies the mast cells release histamine and other symptom evoking chemicals.

Merck & Co, under license from allergy immunotherapy (AIT) company ALK, has launched a ragweed allergy immunotherapy treatment in sublingual tablet form in the US and Canada. Allergy immunotherapy treatment involves administering doses of the allergen to accustom the body to induce specific long-term tolerance.

Control and eradication

Chemical spraying is effective for control in large areas. Because ragweed only reacts to some of the more aggressive herbicides, it is highly recommended to consult professionals when deciding on dosage and methodology, especially near urban areas. Effective active ingredients include those that are glyphosate-based(Roundup, Glyphogan, Glialka), sulfosate-based (Medallon), and glufosinate ammonium-based (Finale 14SL). In badly infested areas usually 2 to 6.5 liters of herbicides are dispersed per hectare (approx. 0.2 to 0.7 US gallons per acre).

Where herbicides cannot be used, mowing may be repeated about every three weeks, as it grows back rapidly. In the past, ragweed was usually cut down, left to dry, and then burned. This method is used less often now, because of the pollution caused by smoke. Manually uprooting ragweed is generally ineffective, and skin contact can cause allergic reaction. If uprooting is the method of choice, it should be performed before flowering. There is evidence that mechanical and chemical control methods are actually no more effective in the long run than leaving the weed in place.

Fungal rusts and the leaf-eating beetle Ophraella communa have been proposed as agents of biological pest control of ragweeds, but the latter may also attack sunflowers, and applications for permits and funding to test these controls have been unsuccessful.

Ambrosia artemisiifolia, common ragweed, is the most widespread plant of the genus Ambrosia inNorth America. It has also been called annual ragweed, bitterweed, blackweed, carrot weed, hay fever weed, Roman wormwood, stammerwort, stickweed, tassel weed, and American wormwood. It is native to North America but a widespread and common invasive weed in much of South America, Australia and Eurasia.

The species name, artemisiifolia, is given because the leaves were thought to bear a resemblance to the leaves of Artemisia, the true wormwoods.

Description

Common ragweed grows to about one meter (3 feet) in height. Its wind-dispersed pollen is a strong allergen to many people with hay fever. Common ragweed emerges in the late spring, and sets seed in later summer or fall.

Invasive species

It has become an invasive species in some European countries, and in Japan, where it is known as butakusa —pig grass.

Common ragweed is a very competitive weed and can produce yield losses in soybeans as high as 30%. Control with night tillage reduces emergence by around 45%. Small grains in rotation will also suppress common ragweed if they are overseeded with clover. Otherwise, the ragweed will grow and mature and produce seeds in the small grain stubble. As of 2005 several herbicides were effective against common ragweed, although resistant populations were known to exist. In 2007 several Ambrosia artemisiifolia L. populations were glyphosate resistant, exclusively in the USA.

As of 2014 the ragweed leaf beetle, Ophraella communa, has been found south of the Alps in southern Switzerland and northern Italy. Many attacked plants completely defoliated.

Phytoremediation

Ambrosia artemisiifolia is used in phytoremediation projects, removing heavy metals such as Lead from the soil.

The cache is a tied in, camoed, "micro" pill bottle, the push hard to both open and close kind. Please BYOP, no tweezers and put back as you found it, or better.