Boomboos are monocotyledonous plants in the true grass family Poaceae, subfamily Bambusoideae, tribe Bambuseae. Their stems and leaves have conspicuous differences to other Gramineae plants. The stems are culmed and erected, are jointed with regular nodes; each node bears one leaf and may also have one to several side branches. Those leaves extensively branched, distichous and parallel-veined. Leaves differentiated into a lower sheath hugging the stem for a distance and a blade with margin usually entire. They spread mainly through their roots and/or rhizomes, which can spread widely underground and send off new culms to break through the surface while raining season. During bamboos growth, there is a protection organ– culm which is an important classification feature.The flower of bamboo is part of shape characters, but bamboo rarely blossoms. Some of these species are monocarpic, the plant dying after the seed matures around 1-2 years; in general, people believe bamboo blossom is an unlucky sign. Actually bamboo blossom is a nature life cycle which is thought to have evolved to reduce the effect of predators of the seed.