But if you cut grass, you don't hurt it at all. Also, grasses, unlike other plants, can replenish their leaves. A blade of grass is the end of a long narrow leaf. If you trace a grass blade back to the stem on a tall grass plant, you see that the blade comes from a sheath wrapped around the stem. At the base of that sheath is a node, a place where the stems of some grasses have a slight bulge.
Nodes are the places where new growth happens in a grass plant.
This capacity to add new material to old leaves is characteristic of grasses. Other plants generally don't have this ability. An oak tree grows new leaves every year, but can't replace part of an existing leaf. An oak leaf grows to a certain mature size and stops. If part of an oak leaf is cut away, it doesn't grow back.