Yerba Mate

Ilex paraguariensis

Yerba mate is a widely-cultivated, medium-sized evergreen tree that can grow to 20 m high in the wild. Commonly, when cultivated, it is pruned into a shrubby, 4-8 m tall tree to make harvesting easier. Yerba mate is in the holly family, and bears holly-like leaves that are quite stiff and leathery. In the wild it grows near streams, and thrives at 1,500-2,000 feet above sea level. It has graceful, full-leafed branches, and white flowers that produce small red, black, or yellow berries. It is yerba mate's tough, leathery leaves that are used medicinally and as a natural, refreshing tea beverage throughout South America. Yerba mate is indigenous to Paraguay, Brazil, Argentina, and Uruguay; however, it is now cultivated in many tropical countries to supply a world demand for its leaves.
Yerba mate was has been used as a beverage since the time of the ancient Indians of Brazil and Paraguay. In the early 16th century, Juan de Solís, a Spanish explorer of South America's famed La Plata River, reported that the Guarani Indians of Paraguay brewed a leaf tea that "produced exhilaration and relief from fatigue." The Spaniards tried the beverage and liked it. Their subsequent demand for the tea led the Jesuits to develop plantations of the wild species in Paraguay and yerba mate became known as "Jesuits' tea" or "Paraguay tea." 

The wild plant has a distinct aroma and taste that has not been matched by plantation cultivation. In South America yerba mate is considered a national drink in several countries; in Europe, it is called "the green gold of the Indios." In Brazil and Paraguay (leading exporters of mate), some production still comes from wild stands-most of which is found in the humid depressions of the foothills. It is not unusual for one wild tree to yield 30-40 kg of dried leaves annually. In wild harvesting, mate gatherers, called tarrafeiros or yebateros, travel through the jungle searching for a stand of trees (called a mancha). Harvesting is done between May and October, when the tree is in full leaf. Leaves are picked from the same tree only every third year, which protects it for subsequent crops. Most of the mate in commerce today, however, comes from large cultivation projects in Paraguay and Uruguay.

The word mate is Spanish for "gourd," and refers to the small gourd cup in which the tea beverage traditionally is served throughout South America. It is also served with a metal drinking straw or tube, called a bombilla, which has a filter attached to the lower end to strain out leaf fragments. The bottom third of the gourd is filled with fire-burned or toasted leaves, and hot water is added. Burnt sugar, lemon juice, and/or milk often is used to flavor the refreshing tea, which occupies a position rivaling that of coffee in the United States. Mate bars are as prevalent in South America as coffee bars are in North America and Europe; mate drinking has deep cultural roots.
Yerba mate also has a long history of use worldwide. In Europe it is used for weight loss, physical and mental fatigue, nervous depression, rheumatic pains, and psychogenic- and fatigue-related headaches. In Germany it has become popular as a weight-loss aid. Yerba mate is the subject of a German monograph which lists its approved uses for mental and physical fatigue. In France yerba mate is approved for the treatment of asthenia (weakness or lack of energy), as an aid in weight-loss programs, and as a diuretic. It also appears in the British Herbal Phamacopoeia (1996) and indicated for the treatment of fatigue, weight loss, and headaches. In the U.S., Dr. James Balch, M.D. recommends yerba mate for arthritis, headache, hemorrhoids, fluid retention, obesity, fatigue, stress, constipation, allergies, and hay fever, and states that it "cleanses the blood, tones the nervous system, retards aging, stimulates the mind, controls the appetite, stimulates the production of cortisone, and is believed to enhance the healing powers of other herbs." Yerba mate now is cultivated in India, and the Indian Ayurvedic Phamacopoeia lists mate for the treatment of psychogenic headaches, nervous depression, fatigue, and rheumatic pains.
The primary active chemical constituency of yerba mate comprises xanthine alkaloids (caffeine, theobromine, and theophylline), saponins, and 10% chlorogenic acid. Sterols resembling ergosterol and cholesterol are also present in yerba mate, and novel saponins have been discovered in the leaf (and named matesaponins). Saponins are plant chemicals with known pharmacological activities, including, as recent research shows, stimulating the immune system. In addition, yerba mate leaf is a rich source of vitamins, minerals, and 15 amino acids.
This information is gathered directly from https://rain-tree.com/yerbamate.htm