1917] MacCAUGHEY—HAWAIIAN FLORA 397 
split or deflected so that these small patches of forest remain 
unscathed. Like the pit crater, the kipuka is often a botanical 
garden in the midst of an arid waste land. 
The lava which surrounds the kipuka, and which may be 15- 
30 ft. higher than the floor of the latter, serves as a protection from 
wild cattle and goats. The kipukas frequently contain a very 
rich flora, a remnant of the original forest cover. These patches 
are usually of very limited area, not more than 2 or 3 acres, and 
are sharply limited by the impinging lava beds. The soil within 
the area is usually deep, black, and rich, and of great antiquity. 
There are hundreds of these kipukas on the lower slopes of the 
great Hawaiian volcanoes, but only those in the arid regions retain 
their individuality. Those in the humid regions are hidden under 
the rain forest. 
Puu Waa-waa.—An ancient cone of minor topographical 
importance, but of extreme interest from the standpoint of the 
geological and botanical history of the archipelago, is Puu Waa- 
waa, in North Kona, Hawaii. This cone is about 6 miles north 
of the summit of Hualalai, near the Loa flow of 1859. Its elevation 
is about 3300 ft..above sea level. It is 500 ft. high, with steep, 
deeply fluted sides. The numerous erosion ravines which radiate 
from the summit and produce this corrugated appearance (the 
native name means “fluted hill’) are 50-75 ft. deep. The cone. 
is composed of volcanic ash and cinders, and exhibits the quaqua- 
versal structure of the typical explosive cone. It has been deeply 
encircled by lava streams from Hualalai and Loa. 
Studies by Cross? of the lavas which underlie Puu Waa-waa 
have demonstrated that these lavas are trachytic, and vastly 
older than the basaltic lavas which now largely cover them. is 
hill is undoubtedly a vestige of an ancient island mass now sub- 
merged beneath newer lava. Botanical explorations by Rock 
have strikingly confirmed the antiquity of the Puu Waa-waa 
region as contrasted with the much younger regions which sur- 
round it. Many evidences of a primitive flora have been found, a 
flora that has largely disappeared from other portions of this 
? Cross, Wartman, An occurrence of trachyte on the island of Hawaii. Jour. 
Geol. 12:510-523. 1904. : 
