So far, about 130 varieties of cranberry are known, some with dark red to black colored fruits. It can be consumed both raw and cooked.
From Wikipedia: “Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus Oxycoccus of the genus Vaccinium. In Britain, cranberry may refer to the native species Vaccinium oxycoccos, while in North America, cranberry may refer to Vaccinium macrocarpon. Vaccinium oxycoccos is cultivated in central and northern Europe, while Vaccinium macrocarpon is cultivated throughout the northern United States, Canada and Chile. In some methods of classification, Oxycoccus is regarded as a genus in its own right. They can be found in acidic bogs throughout the cooler regions of the northern hemisphere.
Cranberries are low, creeping shrubs or vines up to 2 metres (7 ft) long and 5 to 20 centimetres (2 to 8 in) in height; they have slender, wiry stems that are not thickly woody and have small evergreen leaves. The flowers are dark pink, with very distinct reflexedpetals, leaving the style and stamens fully exposed and pointing forward. They are pollinated by bees. The fruit is a berry that is larger than the leaves of the plant; it is initially light green, turning red when ripe. It is edible, with an acidic taste that can overwhelm its sweetness.
Cranberries are a major commercial crop in certain American states and Canadian provinces ... Most cranberries are processed into products such as juice, sauce, jam, and sweetened dried cranberries, with the remainder sold fresh to consumers. Cranberry sauce is a traditional accompaniment to turkey at Christmas dinner in the United Kingdom, and at Christmas and Thanksgiving dinners in the United States and Canada.”
“Raw cranberries have moderate levels of vitamin C, dietary fiber and the essential dietary mineral, manganese (each nutrient having more than 10% of the Daily Value per 100 g serving, as well as other essential micronutrients in minor amounts.”
“As fresh cranberries are hard and bitter, about 95% of cranberries are processed and used to make cranberry juice and sauce. They are also sold dried and sweetened.
Cranberry juice is usually sweetened or blended with other fruit juices to reduce its natural tartness. Many cocktails, including the Cosmopolitan, are made with cranberry juice. At one teaspoon of sugar per ounce, cranberry juice cocktail is more highly sweetened than even soda drinks that have been linked to obesity.
Usually cranberries as fruit are cooked into a compote or jelly, known as cranberry sauce. Such preparations are traditionally served with roast turkey, as a staple of English Christmas dinners, and Thanksgiving (both in Canada and in the United States). The berry is also used in baking (muffins, scones, cakes and breads). In baking it is often combined with orange or orange zest. Less commonly, cranberries are used to add tartness to savory dishes such as soups and stews.
Fresh cranberries can be frozen at home, and will keep up to nine months; they can be used directly in recipes without thawing.”
Urinary tract infections:
“Two comprehensive reviews of available research concluded that there is no evidence that cranberry compounds are effective in preventing urinary tract infections.”
“Raw cranberries are a source of phytochemicals, particularly polyphenols which are under active research for possible effects on the cardiovascular system, immune system and cancer. However, there is no confirmation from human studies that consuming cranberry polyphenols provides anti-cancer or any health benefits.
Cranberry juice contains a high molecular weight non-dializable material that is under research for its potential to affect formation of plaque by Streptococcus mutans pathogens that cause tooth decay. Cranberry juice components are also being studied for possible effects on kidney stone formation.
Cranberry juice is an abundant food source of proanthocyanidins and flavonols and quercetin, which are being studied in vivo and in vitro. However, their effectiveness in humans remains unknown, and is limited by poor absorption into cells and rapid excretion.”
Possible safety concerns:
“The anticoagulant effects of "warfarines" may be increased by consuming cranberry juice, resulting in adverse effects such as increased incidence of bleeding and bruising. Other safety concerns from consuming large quantities of cranberry juice or using cranberry supplements include potential for nausea, increasing stomach inflammation, sugar intake or kidney stone formation.”