This is the limit of tree growth. Above this, old and more recent lava flows 

 cover the ground, which is either bare or covered with a scrubby vegetation such 

 as just described. 



VEGETATION OP THE LAVA PLOWS OP KAU AND SOUTH KONA PEOM SEA LEVEL TO AN 



ELEVATION OP 4200 PEET. 



Between "Waiohinu and Kahuku the vegetation is mainly composed of 0/im, 

 with an occasional sandalwood tree, Santalum Freycinetianum var. latifolium. 

 Lava flows of various ages have descended from the upper as well as the lower 

 slopes of Mauna Loa, some having reached the sea, others having just crossed 

 the government road (1200 feet), while minor flows have descended for only 

 about a mile from their source, after which they cooled and stopped. The 

 neighborhood of Kahuku is the seat of many eruptions, some within the memory 

 of man, as two flows came forth from the southern slopes of Mauna Loa, one in 

 1867, and another in 1887, while as recently as January 9, 1907, after a few 

 slight earthquakes, another flow proceeded in the same direction from an eleva- 

 tion higher than that of the two previous flows. This last eruption emerged con- 

 siderably below the summit of Mauna Loa, pouring forth a stream of aa (rough 

 lava) which divided into two nearly equal streams, with a smaller one between 

 This is, however, not the place to give a description of the behavior of lava flows, 

 and the writer wishes to refer the reader to Dr. Wm. T. Brigham's valuable 

 publication on the Volcanoes of Kilauea and Mauna Loa. All three flows men- 

 tioned above are entirely bare of vegetation, and the half century intervening 

 has not changed the appearance of these various flows in the slightest. The 

 older ones look exactly as does the one of 1907, the only difference being in the 

 color, which is a trifle lighter shade of brown. It is most interesting to note 

 little areas of more ancient flows, perhaps only an acre or smaller in extent, 

 which have not been covered by these flows, and bear an occasional shrub of 

 Nototrichium, with Sadleria ferns, or a small, stunted Ohia. These more recent 

 flows are very irregular in outline, and in the actual flow little islands of many 

 shapes have remained — that is, islands of old lava beds, bearing a typical dry 

 scrub vegetation which was spared by the fiery streams. The last flow at first 

 came forth as pahoehoe (smooth lava), while lower down it assumed aa form, as 

 can be seen along the government road. 



The first plant to settle along the margins of these various flows is Nephro- 

 lepis exaltata, a cosmopolitan fern. Sadleria ferns follow after it or perhaps 

 at the same time, but the former was always to be observed when hardly a grass 

 or weed of any kind was visible. Two branches of the recent 1907 flow are about 

 four miles apart, and this stretch of land is covered by a dry scrub vegetation 

 and occasional trees, such as Xylosma Hillehrandii (Maua), which is by far 

 the most common tree next to Ohia, Antidesma pulvinatum (Hame or Haa), 

 Pipturus (Mamake) and Sadleria ferns. The land of Kahua, which is appar- 

 ently older than Manuka, is of a rough lava nature, with occasional Mpukas, and 



37 



