Because of this Fact they are wide spread and available, often right in your own yard or in the edges of wooded areas and in fields and along roadsides (though roadside cultivation runs risk of chemical contamination from roadway pollution... always flush the root systems with water for at least 12 to 24 hours and wash thoroughly before eating ANYTHING found in a ditch or along a roadway... and consume at own risk and ONLY as a last resort.).
They are extremely edible and high in nutritional value. These plants can be used to supplement your diet to ensure good nutrition even while abstaining from an ever increasing list of known G.M.O. produce which previously provided this nutrition.
Furthermore... because the vast majority of these plants are widely considered to be "weeds to be eradicated" or "undesirable plant species" (even though in many cases they contain MORE of a given nutrient by weight than their agricultural counterparts from which that nutrient is typically obtained) The odds that any company would attempt to genetically Modify them or that they would be capable of hybridization through cross-pollination with known G.M.O. species are EXTREMELY unlikely.
For if nothing more than THAT reason alone... knowing and eating these plants on a daily basis presents a good, long term viable alternative to purchasing and consuming potentially long term DANGEROUS or unhealthy Genetically Modified Produce which may have severe long term negative impacts on the environment, food sustainability, and public health.
SOURCE: WikiHow at http://www.wikihow.com/ (with added personal commentary in some instances)
GRASS: Easiest wild edible EVER! All grass is edible. Anything under 6" is easy to chew and digest. The flavor ranges from intensely sweet to mild to bitter - anyone who's tasted a shot of wheat-grass knows just how sweet grass can be. Grass that's over 6" can either be chewed for juice and spit out, or run through a manual wheat-grass juicer for a healthy shot.
SilverBerry: Look for berries on ornamental shrubs, such as this silverberry. Ebbing's silverberry is frequently planted in cities as bushes and hedges - but it will escape into any disturbed habitat and form thickets. The stems, foliage, and berries are all speckled with silver. The red berries are excellent when fully ripe.
Amaranth (Amaranthus retroflexus and other species)
Native to the Americas but found on most continents, amaranth is an edible weed. You can eat all parts of the plant, but be on the look out for spines that appear on some of the leaves. While not poisonous, amaranth leaves do contain oxalic acid and may contain large amounts of nitrates if grown in nitrate-rich soil. It’s recommended that you boil the leaves to remove the oxalic acid and nitrates. Don’t drink the water after you boil the plant. With that said, you can eat the plant raw if worse comes to worst in smaller quantities.
Burdock (Arctium lappa)
Medium to large-sized plant with big leaves and purplish thistle-like flower heads. The plant is native to the temperate areas of the Eastern Hemisphere; however, it has been naturalized in parts of the Western Hemisphere as well. Burdock is actually a popular food in Japan. You can eat the leaves and the peeled stalks of the plant either raw or boiled. The leaves have a bitter taste, so boiling them twice before eating is recommended to remove the bitterness. The root of the plant can also be peeled, boiled, and eaten.
Known as cattails or punks in North America and bullrush and reedmace in England, the typha genus of plants is usually found near the edges of freshwater wetlands. Cattails were a staple in the diet of many Native American tribes. Most of a cattail is edible. You can boil or eat raw the rootstock, or rhizomes, of the plant. The rootstock is usually found underground. Make sure to wash off all the mud. The best part of the stem is near the bottom where the plant is mainly white. Either boil or eat the stem raw. Boil the leaves like you would spinach. The corn dog-looking female flower spike can be broken off and eaten like corn on the cob in the early summer when the plant is first developing. It actually has a corn-like taste to it.
Lucky you-clovers are actually edible. And they’re found just about everywhere there’s an open grassy area. You can spot them by their distinctive trefoil leaflets. You can eat clovers raw, but they taste better boiled.
Chicory (Cichorium intybus)