A rosette-shaped succulent plant that can reach considerable dimensions, reaching over 1 meter in height and width. Its blue-green leaves are large, long and woody (hence the name "xylon" which means "wood"), which end with a long and sharp spine. Irregularly shaped spines, initially of a reddish brown color, run along its margins, which then tend to turn gray with growth. Flowering occurs from spring to summer, on long central stems which grow up to 3 m high.