The invention refers to a blade of a rotary flow machine including an airfoil having a suction surface and a pressure surface joining each other along a trailing and a leading edge. A radially outward directed airfoil tip and a radially inward directed end joining an inner platform connect the airfoil to a shank at a radial end of the airfoil and providing, at least one shank pocket radially encircled by an axially extending portion of the platform. At least one radially extending rim extends from the trailing edge side of the shank and has an essentially radially orientated first slot for receiving a seal. A mount extends radially inwardly from said shank pocket. The first slot has a first aperture on a shank surface orientated in an axial direction.