Millets grow well in arid and semi-arid environments, requiring less water than any other grain. While developing countries in Asia still produce the majority of the world's millets, Africa is becoming the hub of production. Both are annual grasses with the highly efficient C4 photosynthetic pathway that they have in common with maize, sorghum and sugarcane. Pearl millet is a robust annual, can grow up to 4 meters in height. It has a variable number of tillers, panicle length, seed size, and color.
Finger millet is a smaller grass, adapted to more humid growing conditions.
It too is grown for its straw as well as its grain. Historians believe that pearl millet originated from western tropical Africa more than 3000 years ago and was then taken to East Africa. Similarly, finger millet is a native of Africa that crossed the Indian Ocean to South Asia more than a thousand years ago. Pearl millet is as tough as nails. It produces grain and fodder under very hot and dry conditions, and on soils too poor for sorghum and maize.