40 Transactions. 



Art. IX. — Notes on the Phanerogamic Flora of the Ruahine Mountain-chain, 

 with a List, of the Plants observed thereon. 



By B. C. Aston, F.I.C., F.C.S. 



[Read before the Wellington Philosophical Society, 22nd October, 1913.] 



[Note. — Since this paper was read the author has made further visits to these 

 mountains, and the information thereby acquired is, by permission of the Hon. Editor, 

 allowed to be inserted while the paper is passing through the press. It may be as well 

 to state that the author's knowledge of these mountains is derived from a week spent 

 with Mr. J. S. Tennant, M.A., M.Sc, in the Kaimanawa Mountains (January, 1911); 

 a three-days trip to Makaretu and Umutoi with Mr. Frank Hutchinson, jun. (Rissington), 

 in April, 1913 ; a ten-days journey with Mr. Robert A. Wilson (Bulls) and Mr. Frank 

 Hutchinson, jun., in January, 1914, when a crossing of the mountains was made from 

 Wakarara to Waiouru over what is known as Colenso's Track ; and a solitary ascent of 

 Whariti, 3,020 ft., in March, 1914. The author's warmest thanks are due to his good 

 comrades in these wanderings for their many kindnesses.] 



The Ruahine Mountains being a north-easterly continuation of the Tararua 

 Mountains, from which they are separated only by the Manawatu Gorge, 

 the two ranges possessing many physical characters in common (altitude, 

 aspect, rock, water-supply, temperature), it is not surprising that the plant 

 covering of the Ruahine Mountains is extremely similar to that of the 

 Tararua Mountains in the arrangement of the plants into formations and 

 associations. It will be easier in a short paper such as this to point out 

 the exceptions to this statement which have impressed the author during 

 four brief visits (totalling twenty-one days) to these mountains, in the months 

 of March, April, and January, than to attempt to describe the plant cover- 

 ing of the whole range in a manner which the importance of the subject 

 merits. 



Unfortunately, the foothills up to 2,000 ft. on the eastern side of the 

 range have been to a large degree denuded of forest through farming opera- 

 tions, and a search among the remnants of forests which remain might 

 reveal many facts worthy of record. In these foothills a species not found 

 on the Tararuas is the beautiful Angelica rosaefolia, usually on river cliff- 

 faces. On the river-flats a variety of Sophora tetraptera is seen, with nume- 

 rous trunks springing from or below the ground, the branches having a 

 drooping habit, and the leaves very large. Coprosma tenuifolia is an 

 abundant underscrub of the forest up to 3,600 ft., but is not recorded 

 from the Tararuas. 



One of the most striking ecological facts is the absence of Fagus 

 Menziesii, which constitutes by far the most abundant forest-tree above 

 2,000 ft. up to 4,000 ft. on the Tararua Mountains. It was not observed 

 in the lower forest of the main Ruahine Range, but in the lower forest of 

 the Kaimanawa Mountains, on the eastern side, it is present, ascending to 

 3,000 ft. It is recorded from Tonga riro National Park by Cockayne, and 

 from the higher Waimarino by E. Phillips Turner. On the higher forest 

 of the Ruahine and Kaimanawa Mountains it is certainly replaced by Fagus 



