﻿286 Transactions. — Botany. 



ago it did not exist. It was introduced in the year 1868, and planted in 

 one of the ponds of the Acclimatization Society as shelter for the young 

 trout ; iinfortunately the plant was by some means conveyed into the river, 

 where it is spreading with astonishing rapidity. Although pistiliferous plants 

 only have been found in the province, the latter fact is, perhaps, of little 

 importance, as every joint will form roots when separated from the parent 

 plant. As it is sure to prove a far greater nuisance than the water-cress, its 

 introduction is much to be regretted, seeing that the Avon and other small 

 streams must be kept clear for drainage purposes. The spread of this plant 

 over Britain during the last twenty years is one of the most curious and inter- 

 esting problems that has come under the notice of living botanists. About the 

 year 1850 it was found in a pond in the centre of England, and was then 

 supposed to be indigenous ; shortly afterwards it was found in many distant 

 localities, and was proved to be naturalized, the mode of its migration being 

 still a mystery. It is now common all over Britain, and has, in many 

 instances, impeded navigation in rivers and canals, and interfered with the 

 working of water-mills. In most of those places efforts have been made to 

 eradicate it, but with very little success. The Anacharis is greedily eaten by 

 swans, ducks, and other water birds, but this circumstance, instead of being 

 advantageous, is quite the contrary, as small portions of the plant are carried 

 away by these birds and transplanted to other rivers. It will, indeed, be an 

 extraordinary circumstance if this remarkable plant should become as common 

 in ISTew Zealand as it is in Britain. 



Gonmm maculatwni, Linn., the hemlock of England, is to be found in con- 

 siderable quantities in the neighbourhood of Christchui'ch, where it was sown 

 in th.e year 1865 by an herbalist, who, unfortunately, cannot be punished for 

 the injury he has done the province by the introduction of this very poisonous 

 plant. 



I see that Polygonum aviculare is considered by Mr. Kirk to be indigenous 

 to New Zealand, but, after nine years' study of the native Elora, I feel com- 

 pelled to differ from him in this matter. The plant is spreading very rapidly 

 in this province, more especially along the roadsides, where the seeds are 

 carried in the mud on cart wheels, etc. 



In conclusion, I beg to remind the botanists in the Middle Island that now 

 is the time to determine the date of introduction of foreign plants into the 

 country. 



The following abbreviations are used in the list of species : — a. for Agrestal, 

 plants of cultivated land ; aq. for Aquatic, plants growing in rivers, etc. ; 

 p. for Palustral, plants of swamps, etc. ; s. for Sylvestral, plants growing in 

 woods ; V. for Viatical, plants of waysides and waste places. 



