14. MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
DRAGON-TREE FAMILY (DRACAENACEAE)* 
YUCCA SPP. 
At least 16 species of yucca occur on western ranges, of which 
approximately one-half have well-developed, treelike caudices or 
trunks; the remainder are shorter plants with tufts of basal leaves 
and no conspicuous stem save when the flower stalk is produced. 
One of the chief difficulties with yuccas as forage is that they are 
fiber-producing plants and that these fibers are apt to cause digestive 
trouble unless cut or torn into short fragments so that they can be 
readily eliminated. Bloating, choking, and impaction are some- 
times caused by soapweed feeding, but these can usually be avoided 
by proper preventive measures. Bloating rarely occurs except at 
the first feeding, the cattle soon becoming accustomed to the soap- 
weed and developing a fondness for it. Choking and impaction 
seldom occur except from the use of hand-chopped material. 
Soapweed (Yucca elata)® (pl. 1, A), so named because of the 
saponaceous, emollient roots which are locally and to some extent 
commercially employed for soap, is typically a small tree, or treelike 
plant, with naked woody stems 4 to 6 feet high and 8 to 6 inches 
in thickness. Where, however, moisture and soil conditions are 
favorable it is sometimes 30 feet high, and with a somewhat stouter 
bole. Mexicans frequently call the species palmilla, and the roots, 
amole. The compound fiower clusters appear in May and June. 
Soapweed occurs in a great variety of soils, but mainly on dry plains 
and mesas, from western Texas, through southern New Mexico and 
southern Arizona into Mexico. Forsling (4/) has called attention 
to its frequent association with black grama (Bouteloua eriopoda) 
in sandy soil. On sand hills, where it often reaches its best develop- 
ment, it is frequently the most conspicuous plant in the landscape. 
Soapweed makes but a slow growth, the stem putting on from 
1 to 2 pounds yearly in weight; where the plants are utilized as 
emergency feed, a rotation of 10 or 15 years is necessary to establish 
a perpetual supply. Fortunately cutting does not kill them and they 
will sprout readily from the root. 
Wholly aside from its undoubted utility in checking wind erosion 
and forming shade for other plants and shelter for range livestock 
in the arid regions it occupies, soapweed is of especial interest and 
significance here as an emergency feed for cattle and sheep in periods 
of prolonged drought. The juices of the plant are sweet and attrac- 
tive to livestock and the coarse pulp, although deficient in protein, 
has fattening qualities. Special types of chopping and shredding 
machines have been devised for converting soapweed into suitable 
emergency feed (70, 41). The blooms and growing tip in the center 
of the upper leaf circle also form an important part of the forage for 
cattle in the late spring and early summer (4/7). 
Small soapweed (Yucca glauca), known also as soapweed yucca, 
ranges eastward and northward from New Mexico as far as Missouri 
and South Dakota. The forage value of Y. glauca, except as silage 
4Many botanists prefer to merge this group in the Liliaceae or lily family. 
5 The name “ soapweed’’ is also in common use for Yucca glauca and for the south- 
eastern Y. angustifolia. In horticulture these plants are known as yuccas, and the hame 
soaptree yucca has been proposed for Y. elata. 
