When the supply of sugars from the leaves exceeds the demand for new leaf development and growth, certain grass species may develop a rhizome. A rhizome is a segmented, subterranean, modified stem arising from an adventitious bud in the crown zone. Rhizomes may occur on cool and warm season grasses and may be determinate or indeterminate. Determinate rhizomes are short and turn upward to form a new aerial shoot (rhizome daughter plant). The rhizome growth has three phases: downward, lateral, and upward.