The soil is, in general, thin and porous and does not retain moisture; consequently, the long dry season turns the country into a barren desert, relieved only by vegetation along the riverways and mountain ranges, and by the hardy, widely distributed Carnauba Palm "(Copernicia cerifera)," which in places forms groves of considerable extent. Some areas in the higher ranges of Serra da Ibiapaba, Serra do Araripe and others are more appropriate for agriculture, as their soil and vegetation are less affected by the dry seasons.