Si'Ki<:nr, Cockaynk, Laixg. — Mount Anoti smith District. ;-]49 



modemte-sizod thick piiuiatifid leaves and stout fleshy root). Various 

 xerophytic shrubs occur on rock — e.g., Hymenanthera dentata var. alpina 

 (cusliion of most rigid stout semi-spinous stems bearing, sparsely, small 

 thick smooth dark-green leaves and with very long deeply descending 

 root), Carmichaelin robusta (flat, assimilating leafless stems about 30cm. 

 tall and very long deeply descending root), Discaria toumatou (described 

 further on), Olearia avicenniae folia (shrub-composite form, much-stunted, 

 leaves thick, tomentose). 



Besides the above a good many of the steppe-plants may occur on rock, 

 the number varying according to the amount of soil and position of rock- 

 surface with regard to sun and wind. 



ih.) Fan. 



AA^herc gullies or gorges open out on to the plain or river-bed there are 

 fans of debris, sometimes of great extent. The vegetation of these depends 

 altogether upon the supply of debris brouglit down by the torrent, and this 

 again is correlated with the plant covering of the gully-walls. Fans are 

 either active or passive, and every transition between the two may be traced. 

 The surface of the fan is much steeper than river-bed in general. There 

 are water-channels, but these are usually dry except during heavy rain, 

 the stream being generally underground. The stones are frequently in part 

 very coarse, and are often piled into comparatively high but quite unstable 

 terraces, liable during any flood to damage or absolute destruction. 



The vegetation commences with the appearance of certain herbs whose 

 *' seeds " are wind-borne, and the formation is markedly open. Competi- 

 tion is altogether absent. These first-comers are : Erect Epilobia {E. me- 

 lanocaulon, E. fnicrophyllum), creeping mat-forming Epilobia with slender 

 interlacing rooting stems (E. pedunculare in various forms. E. nerterioides), 

 herbaceous species of Ioav cushion or rounded mat-forming Raoulias (R. 

 tenuicauHs, E. australis, R. lutescens), and the curious half-dead-looking 

 grey-coloured cupressoid shrub Helichrysum depressum, some 40 cm. tall, 

 with spreading branches bearing a few closely appressed woolly scale leaves. 

 As the substratum becomes stable the tussock-grasses Poa caespitosa and 

 Festuca rubra var., one or both, appear, probably occupying first of all a 

 soil-making Raoulia cushion or patch ; MueMevbechia axillaris forms exten- 

 sive circular patches ; the creeping fern Blechnum penna marina, its leaves 

 thick and stunted, forms considerable colonies ; the vegetation gets closer 

 and typical steppe is installed. 



On the other hand, the vegetation may develop otherwise, and the stable 

 but quite stony ground be occupied by a shrub steppe of almost pure Dis- 

 caria toumatou, a more or less leafless divaricating shrub 90 cm. to 1-5 m., 

 or more, tall, furnished with abundant assimilating spines. At a distance 

 such shrub steppe is black in colour and is an invariable sign of fan or 

 of oM river-bed. Between the shrubs there are frequently more or less 

 tussocks. 



(r.) River-bed. 



The procession of events on river-bed is much the same as on fan, and 

 the climax association will be tussotk steppe or shrub steppe {Discaria), 

 or, in the west, modified subalpine scrub. The most important pioneer 

 plant of western river-bed is Raoulia Haastii, which builds true cushions 

 of considerable diameter, green in colour, full of raw humus within, and 

 which can cover not merely the smaller stones, but even enwrap such as 



