New phosphorus-rich phosphorus selenides P_14+xSe (x = 1, 5) were synthesized by reaction of amorphous red phosphorus and SeO₂. The crystal structures of P₁₅Se and P₁₉Se were solved from single-crystal X-ray data (space group Pnma (No. 62); P₁₅Se: a = 9.963(2) Å, b = 3.231(1) Å, c = 13.412(3) Å; P₁₉Se: a = 9.917(2) Å, b = 3.230(1) Å, c = 13.410(3) Å). The structures consist of pentagonal tubes packed collaterally with two-dimensional disorder, which was confirmed by TEM investigations.