50 



It grows vigorously and without apparent intermission. There 

 is no special evidence of a resting period ; the production of new 

 leaves and the extension of the rhizome is ceaseless. 



Ululii occurs throughout the humid and semi-humid regions of 

 all the largest islands of the group, from 500 to about 3,000. feet 

 above sea-level. It never appears upon the littoral, and does 

 not grow well upon the lowlands below 500 feet. Neither does 

 it ascend the higher mountains, but is most abundant between 

 800 and 2,200 feet. It is not found in the strictly arid regions. 

 It reaches its optimum development in the clearings in the native 

 forests — clearings that are sufficient to give it abundance of sun- 

 light, but that leave enough forest to afford protection from the 

 wind. It is partially shade tolerant, but does not grow well 

 under the heavy canopy of the unbroken rain-forest. It is 

 hygrophytic, but not strongly so, and will maintain itself suc- 

 cessfully on semi-xerophytic slopes and ledges. 



UluM is associated with the rugged topography of the montane 

 forests, and is characteristic of steep declivities, ridge crests, 

 valley walls, and similar situations. It is not prevailingly a 

 plant of flat land and does not appear to seek such localities. 

 The chief competitor of uluhi in the forest clearings is the pesti- 

 ferous Hilo grass {Paspalum conjiigatiim) , an introduced species 

 that has become a serious menace in the forests. Hilo grass 

 forms a very dense, impenetrable sod, which, like the uluM, 

 effectually prevents the growth of seedlings of the native trees 

 or shrubs. Uluhi can and does drive out the Hilo grass. 



The iduhi usurps the territory of the native undergrowth in 

 two ways: root competition and smothering. By root competi- 

 tion is meant the slow, inexorable spread of the rhizomes into 

 new territory. This takes place along the entire periphery of an 

 iduhi thicket, and is irrestible by all other vegetation save large 

 trees and bushes. The tough, woody branching rhizomes are 

 able to literally oust all other roots. The mechanical occupation 

 of the soil by the uluhi rhizomes is thorough and complete and 

 results finally in an absolutely pure formation. 



Concomitant with the subterranean invasion is the smothering, 

 action of the masses of wiry, interlocking foliage. The erect 



