Yams are any of the ten economically important species of Dioscorea, a genus in the monocotyledonous family Dioscoriaceae. These species, all tropical in their origin, are cultivated for their edible tubers. In Ethiopia, some aerial yam germplasm collection and conservation works have been started by research centers and Institute of Biodiversity Conservation (IBC). Until now the collected accessions have not been properly evaluated and their attribute remains unknown by breeders. So, detailed descriptions of accessions based on morpho-agronomical characters have tremendous impact on the conservation and genetic improvement of the crop is illustrated in this book.