F. W. Oliver 29 



THE ORIGIN OF SPARTINA TOWNSENDll. 



This species of Spartina is unknown anywhere in the world except 

 at Southampton, where it originated, and in the adjacent waters which 

 it has since invaded. There is no reason therefore for regarding it, like 

 S. alterniflora, as an introduced plant. On the contrary, it must have 

 been produced in situ. The current hypothesis, though not yet scien- 

 tifically grounded, is that S. Townsendii is a naturally produced hybrid 

 between S. stricta and S. alterniflora. This view we owe to Dr 0. Stapf 

 who has also made available a great deal of botanical information 

 bearing on the plant. 



This hypothesis is strengthened by the fact that at the mouth of the 

 River Adour, near Bayonne, where, as at Southampton, S. stricta and 

 alterniflora also occurred side by side, a new form named S. Neyrautii, 

 having much in common with S. Townsendii, has appeared. The pre- 

 sumption is of course that both forms are spontaneous hybrids which 

 have appeared at the only spots where such a thing was possible, i.e. 

 at the only known spots where the two parent forms occurred together. 



In support of the hybrid nature of S. Townsendii the extraordinary 

 vigour of its growth and spread may be cited. In this connection atten- 

 tion has recently been drawn by Dr Augustine Henry to the hybrid 

 nature of not a few forest trees of great vigour of growth and large 

 output of timber. Dr Henry was so much impressed by the matter that 

 he has engaged in the experimental production of hybrid trees with a 

 view to providing forms suitable for use in afforesting the British Isles 1 . 



On the other hand if Spartina Townsendii is really a first cross and 

 if, as seems almost certain, it is largely propagated and spread by seed, 

 it is surprising that there is no evidence of segregation, i.e. of separation 

 into the parent forms. 



This anomaly needs clearing up, and, now that it is of general interest, 

 it is much to be hoped some competent plant breeder may be disposed 

 to take up the matter experimentally. 



OCCURRENCE AND ECOLOGY. 

 The ground on which Spartina thrives best is the soft mud flats 

 within 3 ft. of high water mark, such as are characteristic of Poole 

 Harbour and Southampton. Prior to its appearance these flats were 

 extensively occupied by the sea grass {Zoster a), the ribbon-like leaves 

 of which lie prone on the mud. With the advent of Spartina as the tufts 



1 A. Henry, The Artificial Production of vigorous trees, Journ. Dept. Agr., Ireland, 

 Oct., 1914. 



