452 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



cereus. This blooms en masse at intervals of several months and 

 produces a remarkable display. The flowers open in the evening 

 and close the follow ing morning, so they must be observed by the 

 light of lanterns. The writer was so fortunate as to obtain photo- 

 graphs of this hedge early in the morning. 



Two shrubs are very commonly used for hedges, but it is the 

 foliage instead of the flowers that is attractive. One is the acalypha 

 {Acalypha wilkesiana), a plant of the family Euphorbiaceae, with 

 simple leaves of various shades of brown, pink, and yellow. The 

 other is a species of the family Araliaceae (Nothopanax guilfoylei), 

 with pinnate leaves, consisting of five to seven white-margined 

 leaflets. The croton (Codiaewm vainegatum), an ally of the 

 acalypha, is sometimes used for hedges, but more often is grown 

 in clumps as a lawn ornamental. The narrow leaves are variously 

 spotted and mottled and often spirally twisted. 



Among the numerous ornamental, woody vines is the bougain- 

 villea (B. spectabilk), which produces a great profusion of red or 

 purple flowers. What appear to be flowers are, however, showy 

 petal-like bracts. 



In addition to those mentioned there are several that are familiar 

 as cultivated trees in California and southern Florida, such as the 

 pepper tree, mango, ironwood (('asu-arina equiscti folia) , banyan, and 

 yellow poinciana (Peltophorum inerme). 



An important and common exotic tree, but now thoroughly natur- 

 alized, is the algaroba or kiawe (Prosopis julifora). Contrary to 

 the usual experience where foreign trees or shrubs have been intro- 

 duced and then run wild, this tree has proved to be a great blessing 

 to -the Hawaiian Islands. The original tree is still alive on Fort 

 Street, Honolulu, where it was planted in 1828 b}^ Father Bachelot, 

 founder of the Catholic Mission. The algaroba now occupies ex- 

 tensive areas in the lowlands on all the islands, especially in the 

 arid belts near the coast on the lee side, where it forms forests to 

 the exclusion of all other plants. Fortunately it is very useful in 

 two ways. The flowers are the source of honey of which commodity 

 hundreds of tons are produced annually. The pods furnish a nu- 

 tritious feed for stock. The foliage is not eaten but the pods as they 

 fall from the trees are eagerly sought b}* all kinds of domestic 

 animals, and in the dry season are an important or sometimes the 

 only source of forage upon the ranches. Their value as fodder has 

 led to the invention of machinery to pulverize the pods so that they 

 may be more completely and economically used. The algaroba is 

 freely planted as an ornamental tree because of its graceful aspect 

 and feathery, drooping branches. 



Contrasted with the satisfactory results following the introduction 

 of the algaroba we have the conspicuously disastrous effect of in- 



