Patu

These examples of Patu or Hand Club are made of native New Zealand Totara wood. They both have elaborate surface decoration. Such clubs were used by the Maori warrior in hand-to-hand fighting where split second action is required. A loop of dog skin or strip of woven flax as shown in the lower example is passed through the hole at the butt and round the hand and thumb to provide a firm grip for one-handed use in combat.

Mere

A Mere is a short flat club shaped like a large tear drop. It is the same design as a Patu; but the difference is that the Patu is made of wood, stone, or whale bone whereas a Mere is made of nephrite jade (pounamu or greenstone).  These weapons were held in one hand with a wrist band made of either plaited flax or dog skin and were used in close hand to hand combat.  These weapons were also symbolic signifying high status and authority.

A mere was a really deadly weapon in close quarters hand to hand combat because with its sheer weight it could scalp an opponent when used against the head or cause severe injury within the abdomen when used to strike/jab an opponent in the body.  A really nasty piece of weaponry!

For some more information on the Mere have a look at https://en.wikipedia.org/wiki/Mere_(weapon)