Forest fire is a complex phenomenon in which the levels of description cover a huge range, from the details of the kinetics of gaseous combustion up to the characterization of vegetation as a fuel. An accurate description of the reaction mechanisms encountered in those flames is currently impractical for predicting behaviour of forest fire at the field scale. There is a need for a reliable model for gas oxidation which is very simple and usable in wildland fire models. In this study, the structure of an axisymmetric laminar and time-varying non premixed flame of pine needles is investigated both experimentally and computationally. The gases released from the pyrolysis of pine needles were analysed by means of a tube furnace apparatus connected to a gas chromatograph. An original experimental procedure was also elaborated in order to generate an unsteady, axisymmetric, non-premixed laminar flame for such pine needles. Using numerical methods the transient equations for the conservation of mass, momentum, energy and chemical species were solved for the flame as well as the radiative transfer equation. The calculated distribution of temperature agrees well with the experimental data recorded as a function of time, at different heights in the flame. A very simple formulation for fuel oxidation which can be incorporated in models of forest fire spread is proposed.