Starch grains in eddo tubers by SEM. Eddo tubers (eddoes) are the smaller variety of Colocasia esculenta tubers, also known as taro root. The skin is purplish brown to brown and the flesh white. Taro root is toxic in its raw form. The dimples (depressions) in the starch granules are the imprints of protein bodies with which they had been tightly packed in the tuber cells. Enhanced SEM. Image width: 32 micrometers. Magnification: 3,125x if the image is printed 10 cm wide.