IN EXTRA-TROPICAL COUNTRIES. 359 



extreme hardness. It is -used for gun-carriages, crooks of ships, 

 railway-sleepers, tools, gauges, ploughs, house and bridge posts 

 ' (Laslett). It is as indestructible as iron, hence locally called iron- 

 wood j a rifle shot at 20 yards distance will scarcely cause any 

 penetration into it (Colonel Blake). Neither the teredo nor termites 

 will touch the heartwood (Hooker). It can only be sawn up in a 

 fresh state. The stem exudes a red gum-resin (Kurz). 



Yucca brevifolia, Engelmann. % 



Arizona and Utah, in the deserts. Attains a height of 30 feet. 

 The whole plant can be converted into paper (Yasey). 



Yucca filamentosa, Linne. 



The Adam's Needle. From Carolina and Florida to Texas and 1 

 Mexico. An almost stemless species. It would hardly be right to 

 omit here the plants of this genus altogether, 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 Four- 

 croyas, by slight frosts. Among the species, with stems of several 

 feet in height, may be recorded Y. gloriosa (L.) and Y. aloifolia (L.), 

 both from the sandy south coast of North America. The former 

 proved hardy at Torquay, England (W. Wood). 



Yucca Treculiana, Carriere. 



From Texas westward. Height of stem up to 50 feet, branched 

 only near the summit. Grand in aspect and also most showy on 

 account of its vast number of white flowers of porcelain lustre.. 

 The fruit tastes like that of the Papaw (Lindheimer). 



Yucca Yucatana, Engelmann. 



Central America. This species attains a height of 20 feet, branching 

 from the base. Y. canaliculata (Hooker) ranges from Texas to 

 North Mexico, and has a stem up to 25 feet high with very long 

 leaves. A variety of Y. baccata (Torrey), extending from Texas to 

 California and Utah, occurs with a stem 50 feet high, but with 

 singularly short leaves (Sereno Watson.) 



Zalacca secunda, Griffith. 



Assam, as far north as 28. A stemless Palm with large feathery 

 leaves, exquisitely adapted for decorative purposes. Before we 

 finally quit the Asiatic Palm we may yet learn from Von Martius's 

 great work how many extra-tropical members of this princely order 

 were already known in 1850, when that masterly work was concluded. 

 Martius enumerates as belonging to the boreal extra-tropical zone 

 in Asia ; From Silhet at 24 north latitude : Calamus erectus, Roxb. ; 

 C. extensus, Roxb. ; C. quinquenervius, Roxb. -from Garo at 26 



