THE MONOCOTYLEDONES 



2043 



Mexico and the southern United States. The stem is short, thick and 

 rarely branched and bears a quantity of long, pointed leaves on its upper 

 part. The flowers are large and are produced at long intervals in very large 

 panicles. The pollination is of peculiar interest and has already been 

 referred to (see p. 1263). 



The leaves of Y. filamentosa and certain other species furnish an 

 excellent fibre, similar to that produced by other members of the family. 



In the Dracaeneae are now included some five genera of which Dracaena 

 is the most important. There are forty species in the temperate and tropical 

 regions of the Old World. They are mostly trees. The best known is 

 D. draco (Dragon Tree). The largest, on Teneriffe (Fig. 1983), was blown 



Fig. 1983. — Dracaena draco. The Dragon Tree. Icod. Teneriffe. 



down in 1868. It was 70 ft. high and 45 ft. in girth, and was said by \o\\ 

 Humboldt to be 6,000 years old, but this estimate has been seriously 

 questioned by later observers. The name Dragon Tree is due to a red resin 

 (Dragon's Blood) exuded from the trunk. The genus Cordyline with 

 fifteen species has the same general habit as Dracaena. Its leaves are 

 sometimes used to provide a fibre. Dragon trees are not uncommonly 

 planted in the south-western parts of Britain. 



The Agaveae have short unbranched stems with crowded leaves which 

 are sometimes fleshy. The flowers are hermaphrodite and produced in 

 large panicles. The plants are monocarpic, and the production of the 

 enormously large inflorescences marks the end of their life. The perianth 

 is developed into a tube enclosing six stamens. 



