A panemone windmill is a type of vertical-axis wind turbine. It has a rotating axis positioned vertically, while the wind-catching blades move parallel to the wind. By contrast, the shaft of a horizontal-axis wind turbine (HAWT) points into the wind while its blades move at right-angles to the wind's thrust. It is a rudimentary and inefficient type of windmill. That is, a panemone primarily uses drag whereas the blades of a HAWT use lift.
Historically the earliest known wind machine was made by the Persians and it was the panemone design, consisting of a wall, with slits, surrounding a vertical axle containing four to eight fabric sails. As the wind blew, the sails would turn the axle, which was in turn connected to grain grinders or some form of water transportation device (though little is known of the actual details of such methods).
