768 MINNESOTA BOTANICAL STUDIES. 



they are not species which are capable of ascending high 

 enough to cross the ridge, and the conditions are such that 

 they cannot extend along the sides, and thus work around the 

 ends. 



The parts explored are only a small proportion of the whole 

 island. The little valley of Pauoa, back of Honolulu, and the 

 heights above it, received the most attention, especially the 

 slopes of Konahuanui, which overlook upper Pauoa and Monoa 

 valleys. Monoa valley itself was not explored. Some work 

 was also done on the western slope of Makiki, and on "Tanta- 

 lus," just above. Several trips were made up Nuuanu valley 

 to the Pali, one about half way up Waiolani, one up Kalihi val- 

 ley to its head, and several to the region of Diamond Head. 

 One trip was also made to Pearl river. Marine algae were col 

 lected at Diamond Head and on the coral reef at one side of 

 Honolulu harbor. 



About four months were spent on the island of Kauai, the 

 most northern of the group, and credited with having the most 

 attractions for the botanical collector. This island is almost 

 circular in outline, and enjoys the distinction of often having 

 an annual rainfall of 200 inches at Hanalei, on the windward 

 side, while Waimea, on the lee side, is one of the hottest and 

 driest places on the group. The highest point is Mt. Waialeale, 

 situated a little east of the centre. It is credited with an eleva- 

 tion of 6,000 feet, but in reality is under 5,000 feet. 



The configuration of the island is very different from that of 

 Oahu. Instead of a long main ridge, with secondary ridges 

 branching out at right angles there is a central elevation in 

 Mt. Waialeale, with ridges radiating from it in all directions, 

 something like the spokes of a wheel. These ridges, at least 

 their lower portions, are broad, and easy of ascent. There is 

 usually a good trail along the backbone of each ridge, made by 

 the wild cattle, which are numerous, and range through the 

 forest everywhere. The lower limit of the forest is at much 

 greater elevations here than on the island of Oahu. It is about 

 700 feet in Hanapepe valley, which is situated beneath Waia- 

 leale, and enjoys considerable rainfall, while above Waimea, it 

 is almost 4,000 feet. The point, then, to which the forest de- 

 scends, depends upon the proximity to the central high point, 

 and to the windward rainy side. 



There are three, and perhaps four distinct floral areas on the 

 lee side of the island, but as my explorations did not extend to 



