39 



THE VEGETATION OF A PORTION OF THE "MINERAL 



BELT." 



After following the easy but gradually ascending track to the 

 Dun Mountain (Nelson) for some miles through noble southern-beech 

 (Nothofagus) forest, the tree-community abruptly comes to a halt 

 and the widest part of the celebrated "Mineral Belt" is entered, 

 its barren-looking vegetation offering a striking contrast to the tall 

 green trees at its margin. This sudden alteration in the nature and 

 aspect of the plant covering is apparently due to the high magnesian 

 content of the soil. But the change, almost without transition, from 

 luxuriant forest to xerophytic shrubs, tussock-grassland, and bare rocky 

 ground to no small extent exaggerates the barren aspect of the " Mineral 

 Belt " vegetation, for really it is not different in appearance or ecological 

 characteristics to certain other allied communities of the so-called " dry " 

 New Zealand mountains. Most of the species, indeed, are common 

 enough, but there are a few local endemics e.g., Pimelea Suteri, 

 Myosotis Monroi, perhaps also the local forms of Poa acicularifolia 

 and Cassinia albida, as also the so-called Coprosma Cunninghamii 

 and a species of Festuca. Such forest-trees as overstep the line are 

 dwarfed to shrubs e.g., Nothofagus fusca, N. cliffortioides, Weinmannia 

 racemosa, and some others. 



The vegetation is made up of shrubland, fell-field, and tall tussock- 

 grassland, the last-named with rather small Danthonia flavescens 

 dominant. 



The following are common members of the shrubland : Phormium 

 Colensoi, Exocarpus Bidwillii, Nothofagus fusca, N. cliffortioides, 

 Pittosporum divaricatum, Hymenanthera dentatu var. alpina, Lepto- 

 spermum scoparium (sometimes dominant, from 6 ft. high to prostrate), 

 Griselinia littoralis, Cyathodes acerosa, Suttonia divaricata, Veronica 

 sp. (apparently related to V. buxifolia, perhaps locally endemic), 

 Coprosma propinqua, C. foetidissima, C. Cunninghamii (or an un- 

 described species), Olearia virgata var., Cassinia albida var. In places 

 the association gets more and more open until it merges into the 

 fell-field. The latter, where the ground is extremely stony with 

 many loose stones on its surface, is represented by but few species, 

 the most interesting being Notothlaspi australe, Pimelea Suteri, 

 Colobanthus quitensis, and Myosotis Monroi. Other species of fell- 

 field are Poa acicularifolia var., Claytonia australasica, stunted Lepto- 

 spermum scoparium, Dracophyllum rosmarinifolium, and Helichrysum 

 bellidioides (very grey in colour). 



The foregoing lists are far from complete, but, in any case, the 

 florula is quite small. It is interesting to note that none of the 

 species of Olearia or Senecio so characteristic of subalpine scrub are 

 present, while the shrubland itself is closely related to river-terrace 

 scrub. 



In conclusion it must be pointed out that the remarkable plant 

 covering so briefly described in this note, together with the virgin 

 forest adjacent, form that splendid national domain the Cawthron 

 Park given by the late Mr. T. Cawthron to the people of New 

 Zealand. 



L. COCKAYNE. 



