458 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



North Kona. The species comprises a comparatively few individ- 

 uals and these are decreasing in number because of the incursions of 

 cattle. Mr. Robert Hind, upon whose ranch at Puu Waawaa the 

 trees are growing, is giving them protection and thus preserving the 

 species from extinction. 



Another species, a close ally of the preceding, is called Kohla dry- 

 narioides. A few years ago the species was reduced to a single 

 plant growing in the dry western part of Molokai. Recently this 

 individual succumbed to the inevitable. Fortunately seeds from this 

 tree had been planted and it is hoped that the species may be per- 

 petuated in cultivation. The writer inspected one of the seedlings 

 in the grounds of Mr. George P. Cooke of Molokai. 



Another genus of this family contains three species, remarkable 

 for the paucity of individuals. All are nearing extinction. Pro- 

 fessor Rock states 1 that of Hibiscaddphus giffordianus there is but a 

 single tree near the Kilauea volcano, and of II. wUderianu$ there is 

 a single one on the southern slope of Haleakala. Of II. hualalaiensis 

 there are about a dozen trees. All are succumbing to the ravages of 

 cattle. 



Aside from the shrubs already mentioned as being pestiferous 

 weeds, the guava and the lantana, there are two others that were 

 introduced at an early date and are now thoroughly naturalized but 

 are not so troublesome as the two just mentioned. These are the 

 klu (Acacia farnesiana) and the false koa (Leucaena glmica) . They 

 are found in waste land especially on the dry side of the islands. 

 The klu is a prickly scraggly shrub with heads of yellow flowers. 

 The false koa is without spines, has heads of white flowers and very 

 flat pods. This species is giving promise as a forage plant. By proper 

 treatment the woody stem may be kept trimmed close to the ground, a 

 succession of young shoots that are suitable for forage being sent ur 



The sensitive plant (Mimosa pudica) a well-known and interests 

 undershrub common in tropical America, has become established ii 

 open dry pastures. The twice pinnate leaves are very sensitive to 

 the touch, so sensitive that they respond to the slight jar of the earth 

 in walking, and will close in the vicinity if one steps heavily among 

 the plants. 



The isolation of the islands has led to the unusual development 

 of certain families or genera of plants. One of these families that 

 attracts the attention of the visitor, is the family Lobeliaceae. There 

 are over 100 species belonging to 6 genera, making it one of the largest 

 families of plants on the islands, the number of species being twice 

 that in the whole of the United States north of Mexico. The family 

 is interesting not only from the number of species, but from the 



1 The Indigenous trees of the Hawaiian Islands, 297. 1913. 



