To obtain a plant belonging to cool temperature lawn, having hot tolerance, capable of reducing a cost for maintaining a lawn and decreasing the use of agrochemicals, and useful as a material for greening a golf course and the like by selecting a plant containing tissues in which the number of chromosomes is polyploidized.

This plant belonging to cool temperature lawn has hot tolerance and contains tissues in which the number of chromosomes is polyploidized. The plant belonging to the cool temperature lawn is preferably created by subjecting a plant, such as bent grass, belonging to the cool temperature lawn to a polyploid expression treatment using a polyploid-inducing agent such as colchicine, selecting plants having polyploidized chromosomes from the obtained plants, and subsequently selecting a plant having strong hot tolerance from the selected plants.