306 



ISLAND LIFE. 



[part II. 



Horace Mann, and of Dr. Pickering, who accompanied the 

 United States Exploring Expedition. 



Considering their extreme isolation, their uniform volcanic 

 soil, and the large proportion of the chief island which consists 

 of barren lava-fields, the flora of the Sandv/ich Islands is ex- 

 tremely rich, consisting, so far as at present known, of 554 

 species of flowering plants and 135 ferns. This is considerably 

 richer than the Azores (439 Phanerogams and 39 ferns), which 

 though less extensive are far better known, or than the Gala- 

 pagos (332 Phanerogams), which are more strictly comparable, 

 being equally volcanic, while their somewhat smaller area may 

 perhaps be compensated by their proximity to the American 

 continent. Even New Zealand with more than twenty times 

 the area of the Sandwich group, whose soil and climate 

 are much more varied, and whose botany has been thoroughly 

 explored, has not double the number of flowering plants 

 (935 species), while in ferns it is barely equal. 



Peculiar Features of the Flora. — This rich insular flora is won- 

 derfully peculiar, for if we deduct sixty-nine species, which are 

 believed to have been introduced by man, there remain 620 

 species of which 377, or more than three-fifths, are quite peculiar 

 to the islands. There are no less than 39 pecidiar genera out of 

 a total of 253, and these 39 genera comprise 153 species, so that 

 the most isolated forms are those which most abound and thus 

 give a special character to the flora. Besides these peculiar 

 types, several genera of wide range are here represented by 

 highly peculiar species. Such are Lobelia, the Plawaiian species 

 of which are woody shrubs from six to twenty feet high, one 

 even being a tree, reaching a height of forty feet. Shrubby 

 geraniums fifteen feet high grow as epiphytes on forest trees, as 

 do some Vacciniums and Epacrids. Yiolets, and plantains also 

 form tall shrubby plants, and there are many strange arborescent 

 compositaB, as in other oceanic islands. 



The aflinities of the flora generally are very wdde. Although 

 there are many Polynesian groups, yet Australian, New Zealand, 

 and American forms are equally represented. Dr. Pickering 

 notes the total absence of a large number of families found in 

 Southern Polynesia, such as Dilleniacese, AnonaceEe, Olacacese, 



