206 Transactions. — Botany. 



back. This thistle is not now so aggressive on newly broken - 

 up land in the county as formerly." 



Every year, during our frequent botanical and entomolo- 

 gical excursions, we discover alien species of plants occurring 

 or observed for the first time in the country. It is note- 

 worthy how isolated and strictly local some species are, and 

 remain almost stationary, while others multiply and disperse 

 over large areas within a few years. Some recent introduc- 

 tions or new arrivals in this district have increased and 

 spread at a remarkably rapid ratio compared to many other 

 species which were earlier comers. On the lOth January, 

 1899, we discovered the first specimens of Polycjonum lapa- 

 thifulmvi met with in the county. Since that date it has 

 spread up the river, and is now annually plentiful, especially 

 on the more silty flats. Seeing that this species spread up 

 along the river, its fine seeds were probably carried in the 

 plumage and adhering to the feet of the numerous sea-birds 

 nesting on the river-flats during the summer and autumn 

 months. On the 20th April, 1900, my late son, Walter 

 Valentine, discovered a few flowermg plants of Stachys annua. 

 This species is mentioned by Bentham as having been only 

 once found in a field in Kent, England, which had been sown 

 with seed obtained from abroad. I subxxiitted fresh specimens 

 of the plant to Mr. G. M. Thomson, Mr. T. F. Cheeseman, 

 and Mr. J. B. Armstrong, and these botanists referred to its 

 naturalisation on the Canterbury Plains of New Zealand as 

 an interesting fact in the artificial distribution of plants. 

 The species is very rare, and occurs in one locality only, 

 where I found five plants in bloom in April last. 



For many years it has been the custom of a number of 

 residents of Ashburton to cart garden - rubbish, including 

 offcast plants and dried seed-bearing stems of plants, and 

 deposit them on the open river-bed. From this source arose 

 several species of plants now abundantly naturalised on the 

 river-flats. I have also observed new-comers appear on the 

 sites where straw and hay had been deposited that had been 

 imported in packing-cases. These were plants that generally 

 compose some of the undergrowth of English cornfields 

 and the chief vegetation of English meadows. They com- 

 prised Carduus ianceolatus, Gapsclla bursa-iMstoris, Papaver 

 rhccas, Lejnchnm rudcrale, Siiene inflata, Senecio vulgaris, 

 Chrysanthemum, seyetuvi, Sonclms arvensis, Polygonum avicu- 

 lare, Lolium i^crcnne, Bromus mollis, Cynosurus cristatus, 

 Holctis mollis, and Avcna fatua. The latter plant has proved 

 a great nuisance in fields of oats for many years past. 



•"Plant Acclimatisation" (G. U. Thomson), Trans. N.Z. Inst., 

 vol. XXX., p. 313. 



