Southwest Colorado Wildflowers, Yucca angustissima and harrimaniae

Yucca angustissima (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Canyons of the Ancients National Monument, April 27, 2005.

Yucca angustissima leaves range from just six inches to over twenty-four inches (as shown at left). Flower stalks grow rapidly to three or four feet tall.

Yucca angustissima (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Canyons of the Ancients National Monument, November 4, 2004.

It is common for Yucca angustissima to be found in colonies of a dozen or more plants sprouted from roots of the parent plant. The plants shown are fairly typical in size -- about a foot high.

Yucca angustissima (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Canyons of the Ancients National Monument, April 27, 2007.

Flower clusters (several feet long) are delicate and very eye-catching in the spring Pinyon-Juniper forest. Flower petals are thick, waxy, and long-lasting. The flower of Yucca angustissima is very similar to that of Yucca harrimaniae (shown below), but usually Y. angustissima flowers are somewhat egg-shaped, i.e., the top and bottom of the flower taper from a blubous center. The base of Y. harrimaniae flowers is broader than the top.

Yucca angustissima (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Corona Trail, Utah, June 7, 2007.

These young developing green seed capsules still have the flower petals hanging on. The capsules will dry to a buff brown, split, and spill their seeds.

Yucca angustissima (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Canyons of the Ancients National Monument, March 13, 2007.

Pack Rats, Deer, and other critters nibble Yucca leaves. This plant was nibbled over the 2006-2007 winter and you can see from the first buff colored row of nibbled leaves below the green that the critters have been returning to nibble for several years. At the very bottom of the plant there are, however, many long leaves indicating that until about five years ago no critters were eating the leaves.

Yucca harrimaniae (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Arches National Park, Utah, May 4, 2005.

Yucca harrimaniae and Yucca angustissima are said to have a number of characteristics that separate them, but in the field it is often very difficult to tell them apart. See the distinguishing characteristics listed at the top of the first page.

Yucca harrimaniae (Narrow Leaf Yucca)
Agavaceae (Agave Family)

Semi-desert, foothills. Woodlands, canyons, openings. Spring.
Corona and Bow Tie Arches Trail, Utah, April 14, 2008.

Notice the hole from the pollinating Pronumba Moth in the seed capsule.