xxm THE HAWAIIAN MOUNTAIN-FLORA 271 



once more in the upland regions 4,000 to 10,000 feet above the sea. 

 We will now endeavour to discover from an examination of the 

 present distribution of the isolated mountain-genera (those non- 

 endemic genera possessing only peculiar species) along what tracks 

 they arrived at the Hawaiian uplands, tracks, as indicated by the 

 local distribution of the species, that have been more or less 

 abandoned since. 



TJie MoiDitain Genera with only Endemic Species. — By referring 

 to the Table on the following page it will be observed that nearly 

 a third of these mountain genera have now their principal 

 homes in the high latitudes of the southern hemisphere. They 

 are components of what Forster and Hooker have termed the 

 •'Antarctic" flora, a collection of plants that range round the globe 

 in high southern latitudes, namely, over Fuegia, New Zealand, 

 southern Australia, South Africa, and the islands of the Southern 

 Ocean, the " Antarctic " islands, as they have been termed. These 

 genera are Acaena, Gunnera, Coprosma, Lagenophora, Astelia, 

 Oreobolus, and Uncinia. (It is necessary to observe that I am 

 entirely indebted to the Introduction to the Botany of the 

 " Challenger " Expedition for my information on the " Antarctic " 

 flora.) 



We are thus led to expect that some of the other mountain 

 genera may have been similarly derived from cool southern 

 latitudes, even though they may be scarcely included in the 

 " Antarctic " flora. This is very probably true of Myoporum and 

 Exocarpus, two genera that are chiefly centred in Australia. A 

 species of Sophora (S. tetraptera) is now one of the most widely 

 dispersed of the plants of high southern latitudes, a circumstance 

 which at all events explains the capacity for transport that the 

 ancestor of the Hawaiian " Mamani " (S. chrysophylla) must have 

 originally possessed (see Chapter XV.). Kinship between the 

 Hawaiian species and southern forms has been found in the case 

 of a few of the widely ranging genera here represented. Thus 

 Decaisne placed Plantago princeps next to P. fernandeziana 

 of Juan Fernandez ; whilst according to Hillebrand, Plantago 

 pachyphylla resembles P. aucklandica from the Auckland Islands. 

 These resemblances are consistently associated with the respective 

 range in altitude of the Hawaiian plants, since Plantago princeps 

 occurs usually between 2,000 and 4,000 feet, and P. pachyphylla 

 between 6,000 and 8,000 feet, the species of greatest elevation 

 being related with the species of highest latitude. It is thus seen 

 that these endemic mountain genera with peculiar species have 



