156 



The Yuccas 



with but little of the perianth bases remaining, narrowed at the apex into a short 

 tip, reddish brown; flesh juicy, bitterish sweet, and of a rather pleasant flavor, 

 with a thick, paper)- inner layer surrounding the seeds; these are rounded triangu- 

 lar, about 7 mm. long, about one third as thick, and marginless or slightly mar- 

 gined. 



The wood is soft, porous, and Hght brown; it is seldom used. The fruit is used 

 as food by the Mexicans, who also utilize the rootstock as a soap. 



5. SCHOTT'S YUCCA Yucca SchottiiEngelmann 



Yucca macrocarpa Engelmann 



This rarely attains its maximum height of 6 meters and is found in southern 



Arizona, especially near Benson and 

 Nogales, and grows also in adja- 

 cent Mexico. 



The trunk is usually unbranched 

 and densely clothed with leaves or 

 leaf fragments; branches, if any, 

 few, short, and erect. The rind, 

 sometimes exposed at the base of the 

 trunk, is about 10 mm, thick and 

 roughened by leaf scars. The leaves 

 are thin but stiff, narrowly hnear- 

 oblong, 7 to 9 dm. long, and 2 to 4 

 cm. wide, smooth and bluish green ; 

 the upper portion is concave, the apex 

 stiffly shai-p-pointed, margins brown, 

 with very few fine threads. The large 

 subglobose flowers, appearing in late 

 summer, are in dense, very hairy or 

 seldom nearly smooth panicles, on short stalks. The fruit is oblong and relatively 

 large, up to i dm. long, black, with thin, edible flesh, when ripe; seeds large, angu- 

 ular, obovate, about 9 mm. long. 



Fig. 



SchoU's Yucca. 



SHORT-LEAVED YUCCA Yucca brevifolia Schott 



This species occurs in the canons and hills of the upper Santa Cruz valley, especially in the 

 vicinity of Nogales, Arizona, usually in clusters, and occasionally tree-like and 2 meters tall. 



The leaves are smooth, light green, stiffly diverging, 3 to 7.5 dm. long, 6 to 25 mm. wide, 

 thick, somewhat curved; the apex is sharp and stiff-pointed, the margin splitting into numerous 

 thread-like fibers. The flowers are in smooth, rather loose panicles on short stalks, relatively 

 small, with a tapering style. The fruit is berry -like, rather large, its seeds 9 to 12 mm. in diameter. 



