trees are important to humankind not only economically, environmentally and industrially,but also spiritually, historically and aesthetically, for they sustain human life through direct and indirect gains by providing a wide range of products for survival and prosperity. However, it is not always easy to define “tree.” A tree is a large, long-lived (i.e., perennial) woody plant that attains a height of at least 6 m (20 ft) at maturity in a given locality and usually—but not always—has a single main self-supporting stem called a “trunk” or a “bole,” which gives off spreading branches, twigs and foliage to make a crown (Venkatesh, 1976; Panshin & de Zeeuw,1980; Hawkins, 1986). Since the diameter at breast height (dbh) of trees is determined internationally at 1.35 m (4.5 ft) above the ground, a tree must be unbranched—i.e., with a single trunk—at least up to 1.5 m (5 ft) from the ground. But this definition does not cover the following (Venkatesh, 1976), which are also considered trees: • Palms are typically unbranched trees with only one trunk (columnar stem), called the “caudex,” which ends in a crown of large leaves. • Bamboos are trees without a main trunk but with a cluster of culms arising from the underground rhizome. These culms are unbranched, with distinct nodes and internodes that give them a jointed appearance.