A low wattage high intensity discharge lamp having a quartz arc tube and a glow starter disposed within a bulbous glass envelope containing an inert gas, such as argon, at subatmospheric pressure. The starter within the envelope comprises a first bimetal connected to one of the arc tube lead-in wires, a second bimetal connected to one end of a conductive support wire sealed through the bulbous envelope, and a fixed first contact attached to another conductive support wire sealed through the bulbous envelope and also connected to the other lead-in wire of the arc tube. The bimetals are electrically connected together at one end which makes a normally closed contact with the fixed contact in the quiescent state of the starter. Energization of the lamp causes short circuit current to flow through the starter to cause flexing of the second bimetal for separating the bimetals from the fixed contact to provide an open circuit thereat and produce a high voltage pulse switching transient across the arc tube electrodes. Upon starting of a discharge in the arc tube, the lamp current flow through the starter is operative to maintain the bimetals separated from the fixed contact. The amplitude of the pulse produced by the starter is controlled by the selection of the gas and pressure thereof within the bulbous envelope.