王棕Roystonea regia是常見的棕櫚樹種，由於此類樹木欠缺形成層所以只會長高卻沒有長粗的特性，當它固定一定的粗度後，棕櫚樹便會隨著樹齡增長而越長越高．此樹正常會有一個樹身中段腫脹(大肚腩)的現象（左上圖）．不過，偶然也出現不正常的束腰現象（左右圖）．當遇上 強風時，腰的位置會最易折斷．有 處理過這個樹種的朋友說，束腰地方的木質較硬，相對地也便不容易隨風擺動來卸去風力．

Roystonea regia is one of the most common palm tree in HK. As palm does not have a cambium layer it keeps growing up but not growing in diameter, the tree will only become taller and taller once its trunk has reached a certain degree of diameter. Generally they have a 『big belly』 like the picture on the top left corner. Sometimes, we can find the abnormal narrower stem phenomenon (right hand corner). It can be easily broken at this location under the strong wind. People who are familiar with this species told that the narrower stem part is too stubborn to swing under the strong wind so it is push down by the wind easily.