(aka: Agave asperrima ‘Marginata’) Agave ‘Grand Duke’ is an amazing creamy yellow-edged selection of the rough leaf century plant, Agave asperrima (scabra), often listed under the invalid cultivar name ‘Marginata’. Agave asperrima ssp. maderensis hails from the rocky hillsides of the Northern Mexico state of Coahuila at 6,000-7,000′ elevation. This slow-growing gem, composed of deeply-channeled green leaves, edged with a wide golden yellow border, will eventually mature into an 18″ tall x 3′ wide, slowly offsetting specimen. When we finally put a specimen in the ground, it sailed through 14F with only a small bit on burn on a couple of older leaves.