From a bird’s-eye view, it is easy to see why dendritic pattern drainage was named after the Greek word for tree, dendron. Branching irregularly and at variable angles, the streams and rills in dendritic drainage systems closely resemble the limbs and twigs of a bare deciduous tree. This most common of drainage patterns occurs in terrain where the underlying rock is uniform in composition and has only very minor jointing and faulting. Lacking features that would direct the course of streams, such a terrain yields the somewhat random patterns of dendritic drainage. By contrast, a trellis drainage pattern occurs over terrain where several structural features of the landscape combine to strongly inﬂuence and direct the course of streams. For example, in a landscape where narrow valleys are separated by parallel ridges, tributaries ﬂow down the steep ridge scarps and join the mainstream in the valley at a nearly perpendicular angle. The resulting rectilinear conﬁguration, remindful of a horticultural trellis, is sometimes also called grapevine drainage pattern.