Abstract: Packaging of biodegradable material comprising a retractable pouring spout corresponding to a trapezoidal opening in the central region of one wall of the packaging. The large base of the opening is located on the side of the upper corners of the packaging. The retractable pouring spout is assembled from an external trapezoidal shape (19) corresponding to the opening and an internal assembly (24, 37) having a narrowed central portion (26) about which two lateral wings (25a, 25b) are articulated by lines (26a, 26b) oriented in the opposite direction from the sides (13, 15) of the trapezoidal shape (19). As a result, the wings (25a, 25b) have clearance with the sides (13, 15) of the trapezoidal opening (19), and the opening of the pouring spout takes place without friction of the lateral wings against the sides of the trapezoidal opening.