In many folklores and literatures, green has traditionally been used to symbolize nature and its embodied attributes, namely those of life, fertility, and rebirth. Stories of the medieval period further portray it as representing love and the base, natural desires of man. In Persian and Sudanese poetry, dark-skinned women, called "green" women may be eroticized. The Chinese term for cuckold is "to wear a green hat." It is because in ancient China sex worker's husband wears Green Headscarf. Green is also used to describe jealousy and envy. In more modern times, the consumption of green M&M's has earned urban legendary status as a purported aphrodisiac. In areas that use the U.S. Dollar as currency, green carries a connotation of money, wealth, and capitalism, because green is the color of United States banknotes, giving rise to the slang term greenback for cash. In Thailand, green is associated with Wednesday on the Thai solar calendar.