Latex of some plants containing long chain hydrocarbons is considered to be a good substitute for liquid fuels or petroleum. Such plants having large amount of latex with long chain hydrocarbons are called petroplants. Cultivation of petroplants is also a part of energy-cropping. Cultivation of these petrocrops was first of all done by Italians in Ethiopia about fifty years back, although actual credit for identifying the petrocrops goes to Dr. Calvin. The most common petroplants belong to families of Euphorbiaceae, Asclepiadaceae, Apocynaceae, Compositae, Labiatae, Sapotaceae, Urticaceae, etc., which have property of converting large amounts of their photosynthates into latex with hydrocarbons. Their hydrocarbon contents can be increased by genetic manipulations (genetic engineering). But commercial production of petroleum or liquid fuel alternative (through petroplants) is in early stage. The use of these petroplants may reduce the pressure on liquid fuel or petroleum.