Smith. — Plants naturalised in the County of Ashburton. 209 



HypochcBris radicata spread with great rapidity, and hore- 

 hound {Marrubium vulgare) became established in large masses 

 on every hill, knoll, and sunny slope where the flocks of sheep 

 camped for the night, and around sheep farms and sheds 

 where the flocks are shorn annually. Its prickly capsules 

 are adapted for clinging to the wool of sheep and the fur of 

 hares and rabbits — all having thus assisted to distribute them 

 over the county. 



The great impetus given to sheep-farming by the frozen- 

 meat industry and the high prices ruling for cereals, together 

 with the use of improved farming -implements and vastly 

 improved methods of tillage, by utilising every available space 

 of land, has greatly reduced the vast numbers of the less 

 useful and injurious species of naturalised plants formerly 

 abundant on many large areas of the plains. On the swampy 

 parts and on the margins of the numerous water - races 

 traversing the plains BanuJiculus sceleratus grows luxuriantly 

 in great profusion. In old pastures B. repens became very 

 plentiful, especially on moist rich land ; but it is now much 

 reduced by frequent cultivation of the land for cropping. 

 Fapaver rhoeas is less plentiful in cornfields than formerly, 

 and P. argemone has made no progress during the last ten 

 years. The latter only occurs in four districts in the county, 

 and is a very objectionable plant in any pastoral country. 



Many crucifers were early arrivals with the foul seed 

 imported in the early days, and many species have spread 

 and become naturalised throughout the county. Brassica 

 campestris and B. sinapistrum have long been great scourges, 

 and have in certain years taken almost complete possession 

 of large cultivated areas. As already noted by Mr. Thomson,''' 

 the water-cress {Nasturtium officinale) grows in all the slow- 

 flowing creeks and springs on the river-bed, and attains to 

 proportions never previously observed in Europe. 



The Garyophyllece are largely represented. Silene inflata, 

 S. anglica, S. qui7^quev^dnera, Lychnis vespertina, Spergula 

 arvensis, and Arenaria serpyllifolia flourish in conspicuous 

 masses on both cultivated and uncultivated land. The 

 fleshy rooted deep-rooting S. inflata and L. vespertina, when 

 well established, cause hard work to plough-horses and 

 expense to farmers in cropping their lands. S. quinque- 

 vulnera grows abundantly, and frequently produces large 

 spikes of finely developed flowers with varying shades of 

 colour. 



The naturalised leguminous plants include some of the 

 most aggressive. The gorse {Ulex europceus) and broom 

 {Cytistcs scopariiLs) occupy many thousand acres of the 



* Trans. N.Z. Inst., vol. xxx., p. 313. 

 14— Trans. 



