Soapweed Yucca

I used to think of yucca as a southwestern plant, but Soapweed yucca, Yucca glauca, is a common plant in Wyoming and throughout the high plains.  Today I saw some on a sunny southern slope west of town from which all the recent snow had already melted. 

Yuccas are only native to the Americas.  I have seen numerous species of yucca in the southwest and California, including the largest species the Joshua Tree, but soapweed yucca is the only yucca in this area.    Soapweed yucca gets its name from the roots that can be ground up and worked into a soap or shampoo.

Jim Greenwood at Naturephotograhers.net explains how soapweed yucca is adapted to its harsh environment: "The Yucca glauca is a plant that is well suited to thrive in the semi-arid climate generally found throughout its range. The word glauca is from the Latin root 'glaucus' which is defined as a bluish or greenish-gray color. Many plants have evolved with this characteristic color, which helps them to reflect the intense sunlight usually present in a semi-arid or arid climate. The soapweed yucca has evolved with many other features which enable it to survive long periods of time without a significant supply of water. The long, pointed, dagger-like spines are actually the plant's leaves....[which] have a concave, gutter-like upper surface that helps to catch and direct rain and melting snow down into the plant's roots. The roots also gather and store water in three ways. The root system consist of a large fleshy storage root, a network of small roots directly below the surface that gather water quickly before it runs off or evaporates, and a long tap root that extends as deep as three feet to collect water further down...roots can and usually do regenerate into a new plant within only a few years after the plant has been severely damaged, destroyed or removed."

Soapweed yuccas bloom in June, with a pretty column of white flowers rising from the middle of the plant.  The flowers, besides being pretty, have an interesting mutually beneficial relationship with yucca moths.  According to the US Forest Service : "Yuccas and yucca moths are the classic example of a plant and animal obligate symbiotic relationship where each organism requires the other to survive. Yucca moths are the only insects that can successfully pollinate yucca flowers and the developing yucca fruits are the only larval food source for yucca moths." 

It is only January, so I'm only dreaming of flowers.  We'll have to wait a while for either the moth or the blooms to appear.