Special. Yucca ssp. Piedras Negras is an unknown and new green Yucca ssp. from the area south of Piedras Negras, Coahuile Mexico. In this area, the species grows in a fairly flat area, between not too high hills. This beautiful green species has not been imported before. It may be a transitional form of Yucca Thompsoniana. This ssp. branches quickly so that multiple copies are soon created. The beautiful grass green leaf is much longer than that of Yucca Thompsoniana. The species has fairly thick stems, and a fairly broad rootfoot, as in Yucca thompsoniana, but also as in the Yucca rostrata from the Valle Cillo area. The species has similarities with Yucca rostrata, but has a different leaf structure (slightly serrated) and lacks the gray-blue wax layer.