Entandrophragma candollei of the family Meliaceae, the mahogany family.
Also called "heavy sapele" and omu (among many other common names), this wood is a close relative of sipo (Entandrophragma utile) and like sipo it is sometimes touted as a mahogany substitute.
my samples: NOTE: these pics were all taken in very bright incandescent lighting ("soft white" at 2700K) colors will vary under other lighting conditions
both sides of a sample plank of kosipo / Entandrophragma candollei --- HUGE enlargements are present. This sample was loaned to me by Mark Peet whom I thank for this and other contributions to the site.