When the river originates from a hill and flow in all directions, the drainage pattern is known as 'radial'. Example : Rivers originating from the Amarkantak. The drainage pattern resembling the branches of a tree is known as 'Dendritic'. When the primary tributaries of rivers flow parallel to each other and secondary tributaries join them at right angles, the pattern is known as 'Trellis'. When the rivers discharge their waters from all directions in a lake or depression, the pattern is known as 'Centripetal'.