This is called the serrate leaf.
"The Wonder Island Boys: Exploring the Island"
Roger Thompson Finlay
After a half hour, peaks begin to peep over the hills at our rear; they come up one by one into sight, each whiter and sharper than the last, until the southern line is a serrate row of them, gradually lifted wholly above the nearer hills.
"A Midsummer Drive Through The Pyrenees"
Edwin Asa Dix
The genus differs from the other tough and pliant ones by the peculiarity of the gills, the gills being notched or serrate on the edges.
"Studies of American Fungi. Mushrooms, Edible, Poisonous, etc."
George Francis Atkinson