|Even a king of the coreward kingdoms|
may favor the length of the staff to
symbolize his power and prestige.
It doesn't have to be wood. A wizard's implement of magical dominion of the natural world may be made of metal or some other material. Ultimately, what matters is length.
In essence, the longer the length, the more spells and spellpower the wand can store. This is viewed in several ways.
First, a wizard stepping out of his house with a staff is the equivalent of a modern day military specialist walking around with a bazooka or a stinger missile or .50 machine gun or worse. That mage is ready for a fight, ready to kick ass and take names and chew bubblegum. Or whatever. These mages tend to be bound for adventure outside of the cities of the Wheel.
However, a wizard stepping out with a cane (essentially a stylized rod) is reasonably powerful, but acceptably restrained for most magic-friendly cities in the Kingdoms of the Wheel. Some have had crafted coiled rods -- effectively staff-length implements if straightened out -- as the equivalent of concealed weapons, but these are frowned upon and dealt with harshly in certain quarters. Silver-grip rod-canes are currently in fashion in the coreward kingdoms, while the crooked root walking canes fetch greater use in the outer kingdoms.
Rare is the wizard with a single wand in the cities of the Wheel Kingdoms. Wand-wielders are spellcasters who have multiple wands -- the right tool for the right job. They have bandoliers and sleeve-hoops to hide their implements of craft, and tend to be quick on the draw when threatened.