THE NATURALISED PLANTS. 133 



are perennials. Rapid vegetative increase . by means of creeping and 

 perhaps rooting stems, the formation of a dense turf, rapidity in 

 termination of seeds, enormous seed-production, special contrivances 

 for seed-dissemination by the wind, tolerance of extreme changes 

 of soil and climate, leaves pressed closely against the ground, deeply 

 descending roots, immunity against attacks of animals afforded by a 

 woolly covering, unpleasant taste, &c., conspicuous flowers for insect 

 fertilisation all these and other beneficial characters are frequent 

 amongst the acclimatised species. 



A plant may remain quite isolated for years and, be apparently 

 incapable of spreading, but an unlooked-for change of conditions 

 may give it just what it requires. Dr. Truby King pointed out to 

 me a most interesting case. At Waitati, on the land belonging to the 

 Mental Hospital, stands a fine example of the stringy-bark (Euca- 

 lyptus numerosa) more than fifty years of age. Originally the vegeta- 

 tion of the place was mixed forest, but this has been replaced by a 

 close growth of manuka heath. Some ten years ago this was burned 

 in the neighbourhood of the tree, and a young forest of gums several 

 acres in extent has sprung up (fig. 59). the new ground and the potash 

 from the fire being eminently suitable for the germination of the gum- 

 tree seeds. At the present time the gum-saplings grow extremely 

 closely. Their height is from 40 ft. to 50 ft. Some are half a foot 

 in diameter, while others are extremely slender. Thousands of manuka 

 seedlings sprang up along with those of the gum ; and it must not be 

 forgotten that manuka, far more than most of the indigenous plants, 

 can reproduce itself again and again after burning, and, can exclude 

 almost all other vegetation. But in this case the greater rapidity 

 of growth gave the gums the victory, and now only a little manuka 

 remains near the margin of this remarkable and quite natural forest- 

 growth. Nor is the above merely interesting biologically : it is equally 

 important from the point of view of cheap afforestation of unproduc- 

 tive areas covered with manuka heath. 



The replacement of the native species by aliens has wrought a 

 remarkable alteration in the appearance of New Zealand. Gone from 

 vast areas is the magnificent tropical forest ; vanishing in many places 

 are even the alpine plants. Fortunately, some time ago the Govern- 

 ment took the matter in hand seriously, recognising that as the 

 indigenous vegetation is one of the great attractions of the Dominion, 

 it should be, in certain places, kept inviolate. And so many small 



