The history of 棍 dates back to the ancient people who live in caves. They were often attacked by beasts, and they do not have any sharp objects to fend themselves. As the mountains had trees(wood), the ancients usually used branches to defend themselves.
The other weapons in chinese wushu are made from metal, or use wood as a handle for metal parts. Only 棍 is purely made from wood. 棍 is easy to craft; from the tip to the bottom there is no radian , only a strong pole made of wood. A 棍's fine craftsmanship is determined by its ability to withstand damage or bending. 棍 is also one of the first weapons to enter the battleground. As the invention of firearms became popular, the 棍 became more of a tool for practising Wushu, pulling out of the military.
棍 has no bladed edges, and is one of Chinese Wushu's weapons that uses "hit". The 棍's length can range from 1.3 to 2.6 meters. The face of the 棍 is usually circular, the thickness is determined if the hand is able to hold it. 棍 is a close-combat weapon, its attacking range is further than the broad sword or sword. But 棍's damage is only of "hit", not so lethal as the sword or spear. 棍 has many different kinds, 少林棍、水火棍、盘花棍 are some of the types.
Sources: http://www.bangbenw.com/rspd/ydjs/zgws/201004/t20100418_44992.shtml
http://www.136b.cn/taobao.php?id=19349
http://baike.baidu.com/view/108272.htm