This work considers the frictional closing of a pre-existing flaw in a natural quasi-brittle orthotropic medium (wood) under compression. The effect of the flaw face friction at multiple orientations of the flaw, on the peak load-bearing capacity are investigated. The failure due to crack growth initiation from the periphery of the pre-existing flaw and its propagation was investigated experimentally and modelled numerically. The experimental investigation was carried out using New Zealand Pine wood with a pre-existing flaw under a quasi-static compression test. In the numerical investigation, an eXtended Finite Element Method (XFEM)-based cohesive zone model (CZM) is employed in the modelling of the local crack initiation and propagation. The onset of the crack initiation is modelled using a stress-based criterion and the progressive degradation due to crack propagation is traction-separation based damage evolution. The XFEM-based CZM captures the crack initiation and propagation consistent with the experimental results. The numerical results also show the influence of flaw face friction on the peak load bearing capacity as well as the local stress response.