Soapweed (Yucca glauca)


Small Soapweed Yucca glauca Nutt. (LILY FAMILY)

Small soapweed is an evergreen perennial 1-3 ft tall arising from a short, large caudex. The alternate linear leaves form a basal rosette and are spine-tipped, leathery, and highly fibrous. The branching rootstock gives rise to clumps of plants. The inflorescence is a raceme of drooping cup-shaped flowers borne on a stout flower stalk 2-5 ft tall. The white to greenish-white flowers have 6 similar perianth members, 3 each in 2 series. The fruit is a drooping, 6-sided, 3-valved capsule.

An interesting obligate, mutualistic relationship has developed between yucca and the yucca moth (Pronuba). The moth enters a flower and proceeds to the anthers, deliberately gathering pollen with mouth parts specialized for that function, storing it under the chin. After collecting a large ball of pollen, it flies to another plant, inserts its ovipositor into the ovary of the yucca, and deposits eggs. Then the moth climbs to the stigma and spreads the pollen from another plant on the stigmatic surface, thus accomplishing cross-pollination. The pollen-laden moth visits other flowers on the same plant, as well as flowers on other plants, ovipositing and pollinating. The eggs hatch, and the larvae consume only a portion of the ovules prior to boring out and dropping to the soil where they imbed themselves to overwinter and emerge as moths when the yucca blooms, to start again this amazing cycle. Neither species can exist without the other, truly a marvelous evolutionary adaptation.

American Indians used the pounded roots as soap, hence the name soapweed. Southwest Indians called the soap "amole," and certain tribes had to wash their hair with it prior to ceremonials. They also used the fibers from the leaves for twine, baskets, sandals, whips, and brooms. Small soapweed also provided food for them. The pulp of the near-ripe pods was eaten as were flowers, buds, and young flower stalks. The young flower stalks were boiled to make a red wine-like drink which was said to make one "brave and valiant." Further simmering made a syrup used for rubbing on rheumatic joints. The root was also used as a laxative.