What is a tropical African asteraceous shrub (Guizotia abyssinica) cultivated for its seeds (called ramtil, or niger, seeds) which yield a valuable oil used for food and as an illuminant called?

ramtil — A tropical African asteraceous shrub (Guizotia abyssinica) cultivated for its seeds (called ramtil, or niger, seeds) which yield a valuable oil used for food and as an illuminant. (Webster's 1913.)

Sources