Naturalisation in Extra- Tropical Countries. 523 



to shocks through its extreme hardness. It is used for gun- 

 carriages, crooks of ships, railway-sleepers, tools, gauges, ploughs, 

 house- and bridge-posts [Laslett]. Almost as indestructible as 

 iron, hence locally called ironwood ; a rifle shot at 20 yards distance 

 will scarcely cause any penetration into it [Colonel Blake]. 

 Neither the teredo nor termites will touch the heart wood [Sir J. 

 Hooker]. It can only be sawn up in a fresh state. The stem 

 exudes a red gum-resin [Kurz]. This tree yields also saporiin. 



Yucca aloifolia, Linne. 



Carolina, Florida, West-India, Mexico, in coast-sand. Stem to 

 20 feet high. With its congeners a fibre-plant. 



Yucca angrustifolia, Pursh. 



From Missouri and Iowa to Colorado, Arizona and New Mexico. 

 Height according to Mr. Green to about 15 feet. One of the 

 hardiest of all. 



Yucca baccata, Torrey. 



Colorado, Texas, Southern California, Utah, Northern Mexico. 

 In its ordinary state not tall ; but the variety Y. filifera (Chabaud) 

 will sometimes produce a stem half a hundred feet high with a 

 diameter to 3 feet. The leaves are singularly short [ S. Watson]. 

 This furnishes the Tambico-fibre for cordage, ropes, rugs and other 

 fabrics. 



Yucca brevitolia, Engeliuann. 



Southern California, Arizona and Utah, in the deserts, ascending 

 to 4,000 feet. Attains a height of 30 feet. The whole plant can 

 be converted into paper [Vasey, Baker]. 



Yucca filamentosa, Linne. 



The Adam's Needle. From Maryland to Florida. An almost 

 stemless species. It would hardly be right, to omit the plants of 

 this genus altogether here, as they furnish a fibre of great strength, 

 similar to that of the Agaves. Moreover, all these plants are 

 decorative, and live in the poorest soil, even in drifting coast-sand. 

 They are also not hurt, as is the case with the t^ourcrovas. by 

 slight frosts. 



Yucca s loriosa. Linne. 



Carolina and Florida, aloii.tr the sandy coast-tracts. Stem not 

 tall, but leaves very numerous. The fibre of the leaves furnishes 

 much material for rope, to supply the wants for ships and boats 

 locally. Yucca-ropes are lighter, stronger and more durable than 

 those of hemp [H. M. Brackenridge]. At Edinburgh the plant 

 bore a temperature of F. with impunity [Gorlie] ; vet the 

 Yuccas generally prosper also in tropical countries. 



