Sorghum is a grass species cultivated for its grain, which is used for food for humans, animal feed, and ethanol production. Sorghum originated in northern Africa, and is now cultivated widely in tropical and subtropical regions. Sorghum is the world’s fifth-most important cereal crop after rice, wheat, maize, and barley. Sorghum grows in a wide range of temperature, high altitudes, toxic soils and can recover growth after some drought. It has some features that make it one of the most drought-resistant crops. And the biomass can be burned and turned into charcoal, syn-gas, and bio-oil.
Ricinus communis, the castorbean or castor-oil-plant is a species of perennial flowering plant in the spurge family, Euphorbiaceae. Its seed is the castor bean. Castor is indigenous to the southeastern Mediterranean Basin, Eastern Africa, and India, but is widespread throughout tropical regions. Castor seed is the source of castor oil, which has a wide variety of uses. Castor oil is an effective motor lubricant and has been used in internal combustion engines. It has historically been popular for lubricating two-stroke engines due to high resistance to heat compared to petroleum-based oils. Whether natural, blended, or chemically altered, castor oil still has many uses. For example, it remains of commercial importance as a non-freezing, antimicrobial, pressure-resistant lubricant for special purposes, either of latex or metals, or as a lubricating component of fuels. In Brazil, castor oil is a raw material for some varieties of biodiesel.