Epharmonic variation and general epharmony. 201 
4. Epharmonic variation and general epharmony. 
The high mountains favour epharmonic change more than the other areas 
dealt with in this book, since not only is there a more diverse variety of edaphic 
habitats, but considerable differences in altitude, and consequently in climate 
come into play. As a result, many alpine plants are eminently plastic, a 
considerable advantage in the struggle for existence and ecesis. The most 
common change is decrease in stature accompanied by increase in xerophily. 
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Fig.'54. Helichrysum coralloides growing on. dry rock but in more exposed position than Fig. 53. 
and forming a eushion; Shingly Range, North-eastern distriet at 1500m altitude. Photo L. Cockayne. 
Thus Zeptospermum scoparium, at times a tree 6 m high in the lowlands with 
a trunk 40o cm in diam., forms a close leafy mat, or indeed turf, less than 5 cm 
deep the shoots rooting abundantly. Fodocarpus nivalis in the lowlands of the 
Western district is a spreading shrub 1.8 m tall, but on fell-hield of the North- 
eastern district, it closely hugs the ground while its leaves from plants of 
different stations might well be deemed those of distinct species. Certain plants 
confined to a definite habitat may appear strongly non-plastie as e. 8. the 
