The Origin of our British Flora 



Co. Cork. The blue-eyed grass (Sisyrhinchium) is found 

 in Galway and Kerry, and Eriocaulon in Skye and West 

 Ireland, but both of them are typical North American 

 species. There are two possible explanations of their 

 presence in Ireland. They may be relicts of that very 

 ancient Tertiary flora, which seems to have entered 

 Europe by way of Greenland and Scandinavia, and 

 which have succeeded in living through all the Ice Ages 

 in these particular spots. * Or they may have crossed 

 the Atlantic perhaps within quite recent times. Drifted 

 timber from America occasionally reaches our western 

 shores, and it is by no means impossible that seeds of 

 Eriocaulon could have been transferred in the crevices 

 of a floating log. It is said that the seeds of Mucuna 

 or Entada, which float over to the Hebrides from 

 America, are sometimes able to germinate. It seems, 

 however, more probable that the Sisyrhinchium has to 

 thank some wandering migrant bird for its introduction 

 to Ireland ; its small hard seeds would appear to be well 

 adapted to this form of transport.-j- 



This short sketch of a very interesting subject will at 

 any rate show that there is still a very great deal to dis- 

 cover before we can understand the origin of our British 

 flora. Before the Ice Age, and even before the intricate 

 changes of climate which characterised Tertiary Europe, 

 several of our common British genera must have existed 

 somewhere. 



The chase of " a panting syllable through time and 

 space " is not nearly so fascinating as the story of a 

 living plant. One of the most successful hunts of this 

 kind is that for the original home of the cinnamons. 

 These were found as fossils in the oldest chalk deposits 



* This is the explanation given by Hartz, who found another American 

 plant (Dulichium) in three interglacial peat deposits in Denmark, 

 t Compare Guppy, l,c. 



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