While I was in California, my daughter and son-in-law took me to their favorite African food store, Specialty Foods, Inc. at 535 8th St., Oakland. I took the opportunity to stock up on some items unavailable locally in central Pennsylvania. Some of them had Nigerian? or slightly differently spelled names: millet stalks (labeled watche leaves), or hwentia (labeled udah-urhirhe), and bambara beans (called bambala beans, African yellow soy beans), along with some smoked herring powder (I'm thinking of making some shito before Thanksgiving), some Ethiopian berbere, and some fonio (aka acha), a tiny, grain, one of those "lost crops of Africa" that is one of the oldest grains of Africa. I haven't had that since I was at the Tamale Institute of Cross-Cultural Studies (TICCS) several years ago. It makes a tasty, very nutritious porridge.
The millet stalks are what traditionally give waakye (rice and beans) its characteristic color. In the U.S. we generally substitute baking soda, as in the recipes linked to above.