Collard greens are various loose-leafed cultivars of Brassica oleracea (Acephala Group), the same species s cabbage and broccoli. The plant is grown for its large, dark-colored, edible leaves and as a garden ornamental, mainly in Brazil, Portugal, the southern United States, many parts of Africa, Montenegro, Bosnia and Herzegovina, southern Croatia, Spain and in Pakistan, as well as in Kashmir region of both India and Pakistan. They are classified in the same cultivar group as kale and spring greens, to which they are genetically similar. The name "collard" is a shortened form of the word "colewort" (cabbage plant).
The plant is also called couve in Brazil, couve-galega in Portugal, kovi or kobi in Cape Verde, berza in Spanish-speaking countries, raštika in Bosnia and Herzegovina and Croatia and raštan in Montenegro and Serbia. In Kashmir, it is called haak. In Congo, Tanzania and Kenya (East Africa), the plant is called sukuma wiki. - Wikipedia, Collard Green Profile
Collard Greens originated in the eastern Mediterranean, but it wasn't until the first Africans arrived in Jamestown, Virginia in the early 1600s that America got its first taste of the dark green leafy vegetable. Greens were just one of a few select vegetables African-Americans were allowed to grow and harvest for themselves and their families throughout times of slavery, and so over the years cooked greens developed into a traditional food. Even after the Africans were emancipated in the late 1800s, their love of greens continued, and they kept handing down their well developed repertoire of greens recipes from one generation to the next.
Though Collard Greens did not originate in Africa, the habit of eating greens that have been cooked down into a low gravy, and drinking the juices from the greens (known as "pot likker") is of African origin. - History Of Greens
We get unique health benefits from collard greens in the form of cancer protection. The cancer-preventive properties of collard greens may be largely related to 4 specific glucosinolates found in this cruciferous vegetable: glucoraphanin, sinigrin, gluconasturtiian, and glucotropaeolin. Each of these glucosinolates can be converted into an isothiocyanate (ITC) that helps lower our cancer risk by supporting our detox and anti-inflammatory systems.
Caffeic acid, ferulic acid, quercetin, and kaempferol are among the key antioxidant phytonutrients provided by collard greens. This broad spectrum antioxidant support helps lower the risk of oxidative stress in our cells. Chronic oxidative stress, meaning chronic presence over overly reactive oxygen-containing molecules and cumulative damage to our cells by these molecules is a risk factor for development of most cancer types. - Worlds Healthiest Foods
Collard Greens are rich in invaluable sources of phyto-nutrients with potent anti-cancer properties, such as di-indolyl-methane (DIM) and sulforaphane that have proven benefits against prostate, breast, cervical, colon, ovarian cancers by virtue of their cancer cell growth inhibition and cytotoxic effects on cancer cells.
Collard Greens are also an excellent source of folates, provides about 166 mcg or 41.5% of RDA. Folates are important in DNA synthesis and when given during peri-conception period can prevent neural tube defects in the baby. - Nutrition & You