Agaricus bisporus (English: Portobello, Portobello mushroom) is a fungus, and the type species of the genus Agaricus. It is native to grasslands in North America and Europe. The fungus grows in the fields and grassy areas. The fungus produces the fruit body that bears spores above ground in late spring to autumn. The cap of this mushroom is hemispherical, grey-brown and 5-10 centimeters (2-4 inches) in diameter which is broad and open with flat scales. The stipe or stem is 6 cm (2 1/3 inch) in height, 1-2 cm wide, and up to 1.5-2.5 cm thick; white which bruised to brown and is smooth; it is cylindrical and bears a narrow thick ring on the upper side. The spores are smooth, oval - round, elliptical and 4.5-5.5 μm × 5-7.5 μm. The spore print is dark brown. The flesh of the fruit body is white, firm which stains brownish when it is bruised. The gills are crowded, narrow, pink and red-brown initially which turns to dark brown having a whitish edge. The flavor of Portabella mushroom is strong with a pleasant taste.

Function::

Prevent Neurodegenerative diseases
The copper therapy showed the effective results in preventing Parkinson's and Alzheimer's disease. The high amount of copper could be harmful leading to copper posing and impairment of brain functions. The experts say that tight regulated homeostatic mechanisms are required to copper to maintain the required supply in the body. 
The low presence of copper leads to the problem in growth and poor development in children. It also leads to the health ailments such as muscle and joint pain, fatigue and poor function of brain.  The studies shows that the low amount of copper in the body slows down the growth reduce the weight as well as height and also slow down the metabolic activity.
Antioxidant action
Selenium counteracts the aging process and enhances the immune system by lowering the free radical damages. Along with Vitamin E, it provides a synergistic effect that enhances the body to combat oxidative stress and prevent the colon and prostate cancer. Selenium eliminates the fat in the cell membranes. It is required to combat the oxidative degradation of cells and prevent the mutation of DNA cells that causes diseases.