XXVI METROSIDEROS 



343 



upper open wooded slopes of Mauna Kea at elevations of 6,000 to 

 7,000 feet, and therefore on the outskirts of the true forest-zone. 

 Here the Ohia Tree, as the Hawaiians name Metrosideros poly- 

 morpha, often grows in close association with the Olapa Tree 

 (Cheirodendron Gaudichaudii). In one locality, for instance, a 

 large Olapa was growing in the fork of an Ohia at about eight feet 

 from the ground, and sending down roots on either side. Some- 

 times the trunks of the Olapa and the Ohia were to be seen growing 

 in such close contact as to look like one tree. In one such case a 

 young tree, four feet high, of Myoporum sandwicense was growing 

 in a fork of the Ohia, whilst in a fork of the Olapa a plant of 

 Vaccinium penduliflorum, three or four feet in height, had 

 established itself This remarkable instance of epiphytic growth 

 also proved to be quite a revelation with regard to the dispersal of 

 seeds in this island. Amongst these four associated plants, which 

 include three trees and one shrub, all except the Ohia, which was 

 probably the original tree, have fruits that would attract frugivorous 

 birds ; and in succession these birds had first dropped a pyrene of 

 the Olapa in the fork of the Ohia, and afterwards the seeds of 

 Myoporum again on the Ohia, whilst finally the Vaccinium seeds 

 were dropped into the fork of the Olapa after it had developed into 

 a tree. 



The mode of dispersal of the seeds of Metrosideros polymorpha 

 now invites our attention. Since the fruits are dry, dehiscent 

 capsules possessing minute fusiform seeds, we are not able to 

 appeal directly to the agency of frugivorous birds to explain the 

 wide dispersal of this species. The seeds are light in weight and 

 remind one a little of those of the succulent fruits of Freycinetia. 

 For purposes of dispersal, however, they must be placed in the 

 same category with other plants with dry, dehiscent fruits and small 

 seeds, such as the Vota (Geissois ternata) of Fiji, a tree that in 

 those islands grows in similar stations. On a later page I have 

 suggested that the seeds of the Vota are dispersed by large bats 

 that visit the trees for the sake of the honey in the red flowers. 

 With Metrosideros polymorpha birds act probably in the same way. 

 We are, in fact, informed by Mr. Perkins that the nectar-feeding 

 birds of the Hawaiian Drepanids now obtain their main supply of 

 this food from the blossoms of this tree. If bats or birds visit the 

 large red flowers of Metrosideros polymorpha for the same 

 purpose, it is not difficult to imagine that they might carry away 

 in their fur or in their plumage some of the small seeds shaken 

 out of old dehiscent capsules. In this connection we may note 



