Armstrong. — On the Flora of the Province of Canterbury. 335 



cress, Nasturtium officinale, has proved very troublesome in the rivers, 

 where it attains a size and strength quite unknown in its native country. 

 Another aquatic, the Canadian pond-weed, Anacharis canadensis, of recent 

 introduction, is now abundant in the Avon and other rivers, where it 

 seriously interferes with drainage and navigation. I am of opinion that 

 the fact of the naturalization of foreign plants in New Zealand furnishes a 

 key to the origin of large portions of the floras of other countries, notably 

 of England and Italy. 



No doubt many of the plants now considered indigenous to those 

 countries have been introduced through the indirect agency of man^ 

 perhaps very many generations ago. I think that this theory is borne 

 out by the fact that all countries widely separated from the great masses 

 of land, and cut off from communication as New Zealand was before its 

 discovery by Europeans, have very few species in common with other 

 countries, and these chiefly such as might be carried by the sea, by stray 

 birds, or by strong winds. 



I have included in my catalogue of introduced plants a few species 

 which are usually considered indigenous, but, after a careful examination 

 of all the evidence obtainable, I am satisfied that they are really introduced, 

 and have no claims to be considered indigenous ; these are, — Cyperus tenellus, 

 Sporoholus elongatus, Kceleria cristata, Alopeciirus geniculatics, Picris hiera- 

 cioides, and Polygonum aviculare. 



Economic Plants of Canterbury. — The most important economic plants of 

 the province are the timber trees, which have already been mentioned 

 when describing the various districts in which they are found. In the way 

 of plants fitted for human food, the native flora has very few species and 

 they are in every way inferior — the two or three vegetables cultivated by 

 the Maoris not being indigenous. The fruits eaten by the natives of the 

 South Island were the berries of the pines, those of the hinau, the karaka, 

 the poroyoro, Solaniun aviculare, &,ndi Aristotelia racemosa ; few or none of 

 which would be considered eatable by Europeans. The sea-side cress, 

 Lepidium oleraceum and the New Zealand spinach, Tetragonia trigyna, have 

 been used by English settlers as pot-herbs. Plants yielding fibre are both 

 numerous and important. Foremost among them are the two species of 

 flax or Phonnium, which are now so well known throughout the world. 

 The two kinds of cabbage-tree or Cordyline yield a fine soft white fibre, 

 nearly as strong as and probably more valuable than the Phormiurn. Astelia 

 grandis also yields a soft brown fibre of considerable strength, and is easily 

 cultivated. Some of the coarser kinds of grasses, such as the tussock, Poa 

 ccBspitosa, Aira, Apera, etc., would no doubt yield fibres of some value. 

 The whole of the fibre-plants mentioned here are very easy of cultivation, 



