Add a starburst to the dry garden with this dioecious yucca relative which forms a large sphere of stiff, narrow, wiry leaves. A trunk will form after many years. Some summer thundershowers or water can be helpful. Appreciates sharp drainage.
"While both D. longissimum and D. quadrangulatum come from Mexico, D. longissimum comes from about 200 miles farther south, in the states of Hidalgo and Queretaro, while D. quadrangulatum has a more northerly occurrence in Tamaulipas, southern Nuevo Leon and northern San Luis Potosi. D. longissimum flowers later in the year, generally after the summer solstice, while D. quadrangulatum flowers in spring. When the two species come into flower, they can be distinguished by the form of the flower spike: in D. longissimum, the flowering section of the stalk is spindle-shaped (wider at the middle and narrowing toward either end), while in D. quadrangulatum it is more compact and shaped like a taper candle (widest at the bottom and narrowing as it goes upward)."
Mature size: 4 - 6 ft tall in a lifetime
Minimum temperature: 10° F
Text from: the Ruth Bancroft Garden & Nursery, Plant Highlight: Dassylirium longissimum, August 2019. https://www.ruthbancroftgarden.org/plants/dasylirion-longissimum/.