Magnesium is mobile in the plant and the symptoms are seen first in old leaves. As the deficiency increases yellowing of the leaves or interveinal chlorosis of new leaves become obvious. Necrosis or leaves dying is possible in severe cases. In its advanced form, magnesium deficiency may superficially resemble potassium deficiency. In the case of magnesium deficiency the symptoms generally start with mottled chlorotic areas developing in the interveinal tissue. The interveinal laminae tissue tends to expand proportionately more than the other leaf tissues, producing a raised puckered surface, with the top of the puckers progressively going from chlorotic to necrotic tissue.