20 SILVA OF NORTH AMERICA. LILIACEZ. 
the segments of the perigone, which are united at the base into a short tube, are keeled on the back, 
thin below the middle, and gradually thickened upward above it to the much thickened concave 
incurved rounded tip, those of the outer rank bemg rather broader and thicker and more prominently 
keeled than those of the inner rank ; they are glabrous with the exception of a few scattered hairs at 
the base and at the apex, or are covered with pubescence on the outer surface. The stamens are about 
half as long as the ovary, with filaments which are villous-papillate from the base, flattened below by 
pressure against the ovary, spreading above and clavately thickened toward the apex, and with anthers 
which do not open and discharge their pollen until the second evening after the expansion of the 
flowers The ovary is sessile, conical, three-lobed above the middle, and bright green, with narrow 
slightly developed septal nectar glands,’ and is crowned with a sessile nearly equally six-lobed star-like 
white stigma penetrated by a wide stigmatic canal. The fruit, which mpens m May or June, is 
spreading or more or less pendent at maturity, oblong-ovate, acute, and tipped at the apex by the point 
of the ovary and the stigma, surrounded at the base by the withered remnants of the perigone, slightly 
three-angled, from two to four inches long and from an inch and a half to two inches broad, hght 
reddish or yellow brown and indehiscent, although when thoroughly dry showing a tendency to split 
between the primary dissepiments; the outer coat, which is sometimes a quarter of an inch thick, 
becomes dry and spongy in texture as the fruit ripens, and closely invests the light brown case-like 
inner coat. The seeds are sometimes nearly half an inch in length, rather less in breadth, and not 
quite one sixteenth of an inch in thickness, with broad well-developed margins to the rim, and large 
conspicuous hilums. 
Yucca arborescens is distributed from southwestern Utah to the western and northern rims of the 
Mohave Desert in California, inhabiting the high gravelly slopes which border arid plains and the lower 
slopes of dry mountain ranges, and, in distinct zones and belts, forming open forests often of 
considerable extent. In Utah, where it rarely exceeds ten feet in height, it forms such a belt five or 
six miles wide on the western slope of the Beaverdam Mountains, at elevations of between 2,300 and 
4,400 feet above the level of the sea. In southern and southwestern Nevada it is not uncommon 
at the base of many of the mountain ranges, often growing in forests of considerable extent at 
elevations of nearly 7,000 feet, and ranging northward nearly to the thirty-eighth degree of latitude; 
in northwestern Arizona it is found in a scattered belt in the valley of the Virgin River, and extends 
southward over the low divide between the Detrital and Sacramento valleys; and in California it 
abounds on the Mohave Desert, where it grows to its largest size, making a belt several miles wide 
along the western margin of the desert, covering the northern foothills of the San Bernardino 
Mountains up to elevations of nearly 4,000 feet, spreading westward up Antelope Valley, and along 
the northern side of the desert to the foothills of the Tehachapi Mountains with forests sometimes 
twelve miles wide, and extending with small and isolated groves nearly to Walker Pass, where it 
becomes abundant again.’ 
The wood of Yucca arborescens is light, soft, spongy, difficult to work, very light brown or nearly 
white. The specific gravity of the absolutely dry wood is 0.3737, a cubic foot weighing 23.29 pounds. 
It has been made into pulp for the manufacture of paper,* and is cut into thin layers, which are used 
as wrapping material or manufactured into boxes and other small articles. 
The seeds are gathered and eaten by the Indians, who grind them into meal.® 
1 Trelease, Rep. Missouri Bot. Gard. iv. 195. of Yucca arborescens into paper-pulp. A quantity of paper was 
2 Trelease, J. c. made from the pulp, and it is said that several editions of the Lon- 
3 Merriam, North American Fauna, No. 7, 352, t. (Death Valley don Telegraph were printed upon it ; but the high cost of manufac- 
Exped. ii.). ture more than consumed the profits of the enterprise, and it was 
* About twenty-five years ago at Ravenna in the Solidad Pass, soon abandoned. (See Shinn, Am. Agric. 1. 689.) 
just south of the Mohave Desert in California, a company of Eng- 5 Palmer, Am. Nat. xii. 647. 
lish capitalists established a mill for the manufacture of the wood 
