1917] MACCAUGHEY—HAWAIIAN FLORA 103 
trees, and some reach the amazing height of 40 ft. Many species 
have a slender, naked, palmlike trunk, closely marked with con- 
spicuous leaf scars. This pole terminates in a large rosette of 
foliage and a showy inflorescence. These and other characters 
give the plant a deceptively primitive aspect. 
The Hawaiian genera are Brighamia, endemic, 1 species; 
Lobelia, 5 endemic species; Clermontia, endemic, 17 species; 
Rollandia, endemic, 6 species; Delissea, endemic, 7 species; Cyanea, 
endemic, about 45 species. There are many features, both struc- 
tural and ecological, which strongly suggest that our lobelias are 
the remnants of a very ancient flora, a flora that has well nigh 
been obliterated by profound geological and climatic changes. 
It is significant to observe that the other islands of the Pacific 
are practically lacking in lobelias. Furthermore, in other parts 
of the world these plants are notably alpine in distribution. Many 
high mountains of the tropics and subtropics are marked by a 
lobeliaceous flora similar to that of our Hawaiian mountains. 
These and other facts in local phytogeography lean strongly toward 
the geological hypothesis that at one time these island mountains 
stood at a much higher level (perhaps thousands of feet higher) 
above the sea than at present. Under this theory the islands as 
they now stand are but the vesiee of a former exten land 
ordinary 
geographic distribution of the ‘Hawaiian arboreal mollusks. ne 
undoubtedly has an application to such phytogeographic problems — 
as are involved in weed attempt to elucidate ihe origin of pee 
Hawaiian lobelias.. . 
