ENDEMIC PALMS OF HAWAII 321 



feet. In these inaccessible habitats tlie pabns maintain a pre- 

 carious footing. The}^ are conspicuously dwarfed and wind- 

 formed, and are usually under 8 to 10 feet in height. How the 

 pabns reached these remote hanging valleys is difficult to under- 

 stand, as no natural agency is known whereby seeds could have 

 reached these stations. The palms have evidently occupied 

 these stations for very long periods of time, and may be the 

 vestiges of much larger primitive groves. 



The life period of the loulus, like that of many other Hawaiian 

 trees, is not known with accuracy. All plant growth in the 

 rain-forests is very slow, and the loulu gives every indication of 

 conforming to this general rule. The average mature loulu is 

 probably at least 50 years old, and a large proportion of them 

 are probably double or treble that age. The active erosive 

 agents along the ravine wall, precipice, and stream-way are 

 evidently the chief factors in tenninating the life of the tree. 

 It is probably true that the lo2ilu rarely dies of old age, but is 

 destroyed by torrent, wind, or landslide. 



The dissemination from higher to lower levels is easily under- 

 stood. The heavy, hard, durable drupes drop from the tree, 

 and are carried by their own weight down the steep slopes which 

 characterize the regions occupied by the rain-forests. They may 

 either lodge in irregularities in the slope or (as very commonly 

 occurs) roll dow^n into the stream. They are carried along the 

 streamway, finally lodging and germinating. Hence it is not 

 difficult to account for the loulu along the valley slopes and 

 streams. 



The young loulu palm is shade tolerant. For many years it 

 must grow under the canopy of the rain-forest. Eventually, 

 however, it lifts its crown of great stiff leaves and receives un- 

 obstructed illumination. The mature pabns are intolerant and 

 do not grow well under the shade of taller trees. In looking 

 across a wooded ravine all of the mature loulus are easily 

 perceived, because they stand out plainly above the other 

 vegetation. 



In view of the unsettled status of Pritchardian species in 

 Hawaii the writer feels that a general statement of the out- 



