Poa pcthidris, L., as a British Plant. 265 



Poa palicstris, Z., as a British Plant. By F. Buchanan 

 White, M.D, RL.S. 



(Read 14th November 1889.) 



Though the occurrence of Poa palustris in Britain was 

 recorded several years ago {Botanical Exchange Cluh Beport 

 for 1879), the finder, Mr G. Mcholson, of Kew Gardens, 

 was of opinion that in the locality where it was found — the 

 banks of the Thames at Kew and Mortlake — it was only 

 naturalised. Mr Nicholson adds the opinion that " it does 

 not seem improbable that it may occur in a wild state in 

 Britain," but does not give the reasons for supposing that it 

 was naturalised only, and not native, on the banks of the 

 Thames, nor does he indicate in what manner it may probably 

 have been introduced. 



In August last, my friend Mr William Barclay, who has 

 set himself the task — a labour of love, however — of carefully 

 exploring a portion of the banks of the Tay, found a grass 

 which he could not at the moment identify. Within a day 

 or two, however, we made it out to be Poet palustris, a 

 determination which was confirmed by the eminent agrosto- 

 logist. Professor Hackel. 



On the banks of the Tay the grass is locally abundant, 

 but so many aliens occur on these banks that the fact of its 

 being abundant cannot in itself be accepted as a proof of the 

 species being indigenous. On the other hand, the presence 

 of the aliens in question is no proof that the Poa is also an 

 alien, since many rare and local plants, whose nativity is 

 undoubted, grow on the same parts of the banks of the Tay. 

 The questions which presented themselves to us in discussing 

 this point were these — " Supposing that the plant is an 

 introduction, how could it have been introduced ? and is 

 there anything in its known distribution to militate against 

 its nativity in Britain ? " The aliens of the Tay banks are 

 all species which have been in cultivation for their beauty 

 or utility. Poa palicstris is not, I believe, a fodder grass* nor 



* In this, it seems, I am mistaken. Dr Aitken kindly tells me that it has 

 been experimentally cultivated near Edinburgh, and promises to be a good 

 fodder grass. I cannot find, however, that it has ever been cultivated in 

 Perthshii-e. A careful search in the pasture fields in the neighbom-hood of 



