Roberto Hernández Ramírez Mexicana de Valores, S.A. de C.V. (Mexican Stock Exchange) - 1974 to 1979, Director - 1972 to 2003; Member of the International Advisory Committee of the Federal Reserve Bank of New York - 2002 to present; Chairman, Asociacion Mexicana de Bancos (Mexican Bankers Association) - 1993 to 1994; Member, Bolsa Mexicana de Valores, S.A. de C.V. - 1967 to 1986; Director of Citigroup since from 2001 to 2009; Other Directorships: GRUMA, S.A. de C.V. and Grupo Televisa, S.A.; Hernández Ramirez received a bachelor's degree in business administration from the Ibero-American University (1964), co-founded "Acciones y Valores de México (Accival)" in
Dioscorea mexicana Dioscorea mexicana Dioscorea mexicana, Mexican yam or cabeza de negro is a species of yam in the genus "Dioscorea". "Dioscorea mexicana" is a caudiciform dioscorea having either a partly to completely above-ground dome-shaped caudex with a thick, woody outer layer up to 3 feet (90 cm) in diameter and 8–10 inches (20 to 25 cm) in height. The caudex of "D. mexicana" is divided into regular polygonal plates that become protuberant with age, and separated by deep fissures. The vigorous annual vines which may reach 30 feet (9 m) long before dying back in winter, that grow up from the