Buchanan. — On the Alpine Flora of New Zealand. 343 



caused by ocean currents of different temperatures impinging on opposite 

 coast lines, or by local hot winds ; but, wliatever may be tbe influencing 

 cause, representative plants of the North Island pass several degrees of 

 latitude southwards on the west side of the South Island, which are not 

 found on the east side of that Island, thus indicating a higher temperature 

 on the west ; and this is also consistent with the alpine flora of the North 

 Island being found at higher altitudes on the mountains of the South 

 Island than on those of the North. 



The alpine flora as observed has a rapid development. This is no doubt 

 necessitated by the short period which intervenes between the melting of 

 the snows and the next seasonal fall. The intense heat of the sun at high 

 altitudes, is no doubt an important element in hastening growth, but the 

 chief cause must be ascribed in many cases to the advanced stage at which 

 the plants have arrived before the melting of the snows in spring has un- 

 covered them. Large plants such as Ranmiculus buchanani were found 

 8-10 inches high, breaking through their snowy covering, with the leaves 

 and flower-buds fully formed ; no sooner, however, did the last film of snow 

 melt from above them, than they burst into flower while the leaves were 

 yet blanched and colourless, and it is probable that in favourable weather 

 seed may ripen in a few weeks. 



On the Mount Aspiring Eange may be seen, covering patches of snow, 

 that peculiar 1-celled plant — Protococcus, or red snow. This plant was 

 observed by Captain Eoss on one of his expeditions to the Arctic regions, 

 covering the surface of the snow over large areas, and penetrating down- 

 wards several feet. 



Pachycladon novcB-zealcmdicE , Hook. fil. 

 Braya novce-zealandia, Hook, fil., Handb. N. Z. Fl., vol. i., p. 13. 



A short depressed alpine plant, covered with stellate pubescence ; root 

 long, fusiform, J-| inch diameter, bearing 1-6 stout branches, each branch 

 terminating in a rosulate head of small imbricating leaves. Leaves in 

 several series |-^ inch long, including the petiole, pinnatifidly lobed and 

 narrowed into flat, short petioles, those on the scapes with longer petioles, 

 and a minute ovoid blade, which is digitately lobed at top ; scapes numer- 

 ous, shorter or longer than the leaves, rising from the branches or root 

 below them, and spreading horizontally, 3-5-flo\^ered ; flowers white, -i inch 

 long, sepals obovate, obtuse, petals longer than the sepals, upper half round, 

 tapering below to a narrow point ; stamens 6, two longer than the others ; 

 pods ^ inch long, j-V i^ch broad, laterally compressed, linear oblong, septum 

 incomplete ; seeds 6-8 in each valve, ovoid, and with vertical ridges. 



Hab. — Mount Alta Eange, 6,000 feet alt. — Hector and Buchanan, 1862 ; 

 A. McKay, 1881. 



