Preliminary Observations Concerning tlie Plant 

 Invasion on Some of the Lava Flows of Manna 

 Loa, Hawaii. 



Chari.es N. Forbes. 



During an excursion on the island of Hawaii for the purpose 

 of collecting botanical material for the Bishop Museum, an ad- 

 mirable opportunity was offered for making observations on the 

 colonization of a portion of the lava flows of Mauna lyoa. Although 

 a limited portion of the mountain has been covered, and observa- 

 tions of this character should extend over a number of years, it is 

 believed that data of enough local interest was obtained for record 

 at this time. 



The region visited extends from Puuwaawaa, over the summit 

 of Hualalai, through the districts of Kona and Kau, mainly at an 

 elevation of 4500 feet, which is just above the dense forest belt. 

 One trip was made to the summit of Mauna Loa on the Kailua side, 

 and from numerous localities the forest was penetrated in all direc- 

 tions; the region below the Government road in Kona and the 

 shore line being the only portions from which a representative 

 collection of plants was not taken. 



This territory is on the dry or lee side of the island, and for 

 that reason the naturalization of plants on the lava flows may vary 

 somewhat from that of the moister regions; but it is believed that 

 the main factors will prove to be the same, except for rapidity of 

 invasion. The general characteristics of the Hawaiian vegetation 

 have been described by several writers,' and in this paper it is the 

 intention to discuss onh- the flora in the immediate vicinity of the 

 flows visited. 



There is probably no better locality in the world for observing 

 the colonization of lava flows than the slopes of Mauna Loa. The 



'Hillebrand, W.: Flora of the Hawaiian Islands, 1888. Guppy, H. B.: 

 Observations of a Naturalist in the Pacitic, vol. ii. Hall, W. L.: The Forests 

 of the Hawaiian Islands, U. S. D. A., Dept. Forestr}-, Bui. 48, 1904. 



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