Yucca elata
Soaptree Yucca
Family: Asparagaceae
This treelike yucca can grow to 6-20 feet tall, usually with 2 to 5 branches, although older clusters can form up to 20 trunks. A spherical head of narrow, flexible leaves crowns each branch. The leaves measure from 1 to 3 feet long, with white margins and fuzzy white fibers along the edges. The showy flower spikes can reach up to 15 feet tall, producing masses of waxy white flowers in the late spring. Flowers are followed by dry capsules with papery black, flat seeds.
Plant in full sun, low water when established. Good drainage is a must. Plants are hardy to -10°F.
Soaptree yucca has an obligate mutualistic relation to its pollinator the yucca moth (Tegeticula yuccsella). The yucca moth pollinates its flowers and moth larvae feed on the developing fruit, decreasing viable seed production by up to 20%. Soaptree yucca aborts many fruits, killing larvae therein; this process is thought to help maintain the mutualistic relationship.
Photo by Mountain States Wholesale Nursery
The flowers of this species (and all species of Yucca) are edible. Native Americans use the fiber of the soaptree yucca's leaves to make sandals, belts, cloth, baskets, cords, and mats, among other items; they also eat the flowers. Inside the trunk and roots of the plant is a soapy substance high in saponins. This substance is used as soap and shampoo, which is used to treat dandruff and hair loss. At least one tribe, the Zuni, use a mixture of soap made from yucca sap and ground aster to wash newborn babies to stimulate hair growth. The Apaches also use yucca leaf fibers to make dental floss and rope. In times of drought ranchers have used the plant as an emergency food supply for their cattle; the chopped trunk and leaves can be eaten.
There is confusion between the word yuca and yucca and this goes back to the father of botany: early reports of the species were confused with the cassava (Manihot esculenta). Consequently, Linnaeus mistakenly derived the generic name for Yucca from the Taíno word for the cassava, yuca. The species, elata, means tall.
Found on mesas, desert washes, sandy plains, and grasslands from 1,500-6,000 ft in southwestern North America, in the Sonoran Desert and Chihuahuan Desert in the United States (western Texas, New Mexico, Arizona), southern Nevada, southwestern Utah, and northern Mexico (Chihuahua, Coahuila, Sonora, Nuevo León). In Arizona, this is one of the more common species seen on roadsides. Yucca elata is widely distributed, although its population appears to be decreasing.
Photo of Yucca elata at Big Bend National Park, by Richard Reynolds, iNaturalist
Yucca elata seed pod, photo by Dicklyon on Wikipedia
Yucca elata flowers, photo by Stan Shebs, Wikipedia
Yucca elata growing in dune at White Sands, New Mexico, photo by Curren Frasch, iNaturalist