The previous robust adaptive beamformer for sparse array enjoys performance improvement due to enhanced degrees-of-freedom (DOFs), while the polarization diversity of signals is not considered. The polarization diversity is an important factor that could be exploited to design a more functional beamformer. Specifically, in this paper, a cascaded sparse array (CSA) composed of diversely polarized antennas, which is polarization sensitive and has reduced mutual coupling, is proposed with a closed-form expression for the array geometry. Then, a polarimetric sparse reconstruction beamformer operating in the joint spatial and polarization domain is proposed for the CSA, and it is capable of suppressing the interferences using the information in the additional polarization domain with enhanced DOFs. As a result, it not only offers reduced costs but also improved functionality, demonstrating its potential value in future wireless communications. The polynomial rooting based joint direction-of-arrival and polarization estimation procedures are then given to support the power distribution estimation in a closed-form manner. Subsequently, the estimated steering vector of the desired signal and the reconstructed interference-plus-noise covariance matrix are combined to calculate the proposed beamformer. Numerical simulations are included to verify the potential advantages of the proposed CSA as well as the superior performance and robustness of the proposed beamformer.