Smith. — Plants naturalised in the County of Ashhurton. 213 



few or no fences on the plains, and merino sheep roamed free 

 over the great expanse of tussocks. Every freshet in the 

 natural water-channels where they grew would also rapidly 

 distribute the seeds of these and other aggressive plants. Mr. 

 John Cochrane informs me that he observed docks attain a 

 height of 7 ft. in these channels in 1860 ; and the year follow- 

 ing he observed the first thistles {Garduus lanceolatus) in 

 Wakanui, and two years later they were plentiful on good 

 land on the tussock plains. At that time they grew annually 

 3 or 4 acres of tobacco, which they cut three times in a 

 season for sheep-dipping purposes. After the tussocks were 

 burned they also sowed seed on the burned areas, which 

 generally produced " more bad plants than good ones." The 

 second year after ploughing the land sorrel {Bumex acetosella) 

 spread over it, and soon took possession if not rigorously 

 checked. Since tilling operations commenced about forty 

 years ago sorrel has been a very aggressive and destructive 

 pest. Polygonum aviculare, the so-called wire- weed, and the 

 var. Driandri, are abundant everywhere. P. mimes, persicaria, 

 convolvulus, and lapathifolmm attain to great perfection on 

 the moist silty river-flats, and display a wealth of flowers 

 during the autumn months. 



"When Mr. Cochrane arrived at the Wakanui sheep-station 

 in 1860 nettles {Urtica dioica, U. urens) were growing about 

 the sheep-yards erected a few years previously. They exist 

 at present in a few hedgerows, but are not troublesome. 



In wet seasons the seeds of Betida alba, Populus alba, 

 Salix fragilis, S. caprea, and Quercus robur v. pedimculata 

 produce seedlings in masses under old trees. The acorns of 

 the oak have been carried by water-races and other streams 

 crossing the plains and deposited in the silt, on which they 

 grow into good-sized trees in a few years. 



In the Coniferce, Pinus insignis, P. pinaster, and C^ipressiis 

 macrocarpa cast fertile seed and became naturalised fifteen 

 years ago. There are other interesting aspects of the naturali- 

 sation of conifers that may be noted. Plants raised from 

 seed of G. 7nacrocarpa grown in the county lack the vigour and 

 grow weaker, more narrow, and more upright than do those 

 grown from imported seed. Notwithstanding that several 

 species of Abies, Picea, and other conifers produce fertile 

 cones and cast seed, I have not up to the present time 

 observed any of them to grow and naturalise under the parent 

 tree. 



The banks of the north and south branches of the Ash- 

 burton Eiver for many miles are overgrown with the weeping 

 willow {Salix babylonica). The Wakanui Creek, from its 

 intake to the sea, a distance of eleven miles, is also shaded 

 by magnificent willows, all self -planted. During gales of 



