23S A NATURALIST IN THE PACIFIC chap. 



about its affinities, and a discussion of the subject will be found 

 on pages 20 and 66 of the Introduction to the Botany of the 

 Challenger Expedition. 



The restriction of these ancient genera of the Polynesian 

 Compositae to the upland regions is of some interest. " The pre- 

 ponderance of Compositae among the high-level plants obtains 

 almost throughout the world." This observation was made by 

 Mr. Hemsley in connection with the flora of the highlands of Tibet 

 {Jo7irn. Linn. Soc. Bot. vol. 35, 1902), where the Compositae 

 constitute about 19 per cent, of the flowering plants ; and I may 

 remark in passing that, according to Mr. Ball, one of the most con- 

 spicuous elements in point of frequency in the higher flora of the 

 Great Atlas is presented by the Compositae which make up between 

 12 and 13 per cent, of the whole flora (Hooker and Ball's Marocco 

 and the Great Atlas). This feature of alpine floras is brought into 

 great prominence in Schimper's recent book on Plant Geography. 



Some of the most lasting reminiscences that the naturalist will 

 bear away with him from the highlands of Hawaii are connected 

 with the Compositae. Those who have ascended the mountains of 

 Mauna Kea and Mauna Loa, will remember that amongst the last 

 plants occurring above the forest zone, and scattered about on the 

 ancient lava fields at elevations exceeding 10,000 feet above the 

 sea, are species of Raillardia and the beautiful " Ahinahina " 

 (Argyroxiphium). It is, however, in the open, scantily wooded 

 region, elevated 6,000 to 9,000 feet, and lying between the true 

 forest zone below and the bare lava slopes above, that the shrubby 

 and arborescent Composite of the large island of Hawaii are most 

 at home. Such regions, as Plillebrand well describes (p. xxiv), are 

 characterised by stunted trees, chiefly Sophora, Cyathodes, 

 Myoporum, and others, associated with arborescent Raillardiae of 

 the order of Compositae. Between them luxuriate other shrubby 

 Compositae of the genera Raillardia, Dubautia, Campylotheca, and 

 Artemisia, together with Strawberries, Raspberries, and species of 

 Vaccinium. 



Botanists have not given us much account of the associates of 

 the interesting genus Fitchia on the uplands of Tahiti. We learn, 

 however, from Nadcaud that in his time these Composite trees and 

 shrubs were spread over the higher region of the island of Tahiti 

 above 800 and 1,000 metres. Cheeseman, to whom we are indebted 

 for the discovery and the description of the Rarotongan species, 

 tells us that this tree, which attains a height of 25 feet in the 

 sheltered valleys, and is much dwarfed on the e.xposed ridges and 



