INTRODUCED PLANTS AND ANIMALS. 243 



sjenitoi' of more than (iO.OOO acres of forest distributed over the entire group. 

 At tirst it grew only at the lower levels, but, little V)y little, succeeding genera- 

 tions have crept higher and higher until now they thrive from the sandy sea 

 beach to 1,500 feet elevation. The lee coasts of Oahu, Molokai, and parts of Ha- 

 waii have been changed from deserts to forests by the algaroba alone. Curi- 

 ously enough, the land which it has taken possession of is usually arid or stony, 

 or so steep that it was considered generally worthless. If left alone they .shade 

 the ground with a dense growth and attain a height of fifty to Sixty feet. When 

 trimmed and thinned, as the.y are in the city, their delightful shade moderates 

 the heat of the tropic sun, allowing the growth of the lawn grass beneath, and 

 in dry seasons protecting it from the direct rays of the sun. Their slender, 

 brittle branches are often too much in evidence to be asthetic in themselves, but 

 nevertheless they have a weird picturesqueness of their own. The trunk at first 

 seems uncouth, but there is a grace and poise to the slender vine-like branches 

 and feathery leatlets as they toss to and fro in the trade wind, that over-balances 

 the ruggedness of the gnarled and twisted trunk. 



In addition to its asthetic qualities the algaroba is one of the most useful of 

 trees. Besides yielding an enormous amount of wood of splendid quality, they 

 are valuable for the pods that are produced with great regularity after the tree 

 is three years old. The jukIs ripen gradually during the summer months, and, 

 next to the grasses, form the most important stock food. They are eaten b.v 

 horses, cattle and hogs with great relish. The hard, horny seeds which are era- 

 bedded in a sweet pulp are not digested by the stock, and hence are in prime 

 condition for growing and are scattered broadcast in this way. 



The algaroba is also our most important honey-producing plant. Bees are 

 exceedingly fond of the nectar of the flowers and the sugar of the beans. Many 

 apiaries in algaroba groves produce hone.v of attractive appearance and superior 

 flavoi'. 



The tree exudes two ditt'erent kiiuls of gum. The most valualjle collects in 

 clear, amber-colored, tear-like masses on the bark. It resembles the gum arable of 

 commerce. As it contains no tannin and desolves readily in water the gum has 

 elsewhere l)een used in laundries and to some extent in the manufacture of gum- 

 drops. In ^Mexico it is also valued for certain medical jn-operties. In Hawaii 

 it has never been collected or used, though ]ar<jc quantities of the gum could be 

 secured. 



CHAPTER XVIII. 



A ra:\ible in a Honolulu garden: part two. 



The Poinci.vna. 



Turning to the purely ornamental trees, first ]ilace is usually given to the 

 scarlet-flowered royal Poinriana,' or to one of the closely allied species or varie- 



