Due to the diverse climatic (annual precipitation, Temperature,… ) and topographic conditions, Ilam province has a wide variety of plants. So far,over a thousand plant species have been collected in the province which are deposited in the Central Herbarium of Iran. More than three hundred species of plants are edible, pharmaceutical and industrial. About 87 percent of the province is covered by forests and pastures. This province has 641,666 acres of forests, dominated by oak, mastic, arjan, almonds, hackberry, sumac and hawthorn. About 33.3 percent of forests are dense and semi-dense and the rest are sparse forests. Of this 641.666 hectars, 440,000hectars are oak trees which some of them have a life-span of 700 years. Tragacanth, manna and honey are some of the products of the province.