The Origin of our British Flora 
carpon, Allium triquetrum, and perhaps the wild gladio- 
lus, but it is very difficult to give a satisfactory list. 
These belong to the west and south of France, Portugal, 
and Spain, and might be supposed to represent an out- 
lying part of the Mediterranean flora. 
They occur along the south coast of England, in 
Ireland, and in some few cases also in the south-west of 
Wales, which seems at first sight to be a very inexplic- 
able sort of distribution. 
But if one takes Bartholomew’s Physical Atlas (Plate 
18), which gives the distribution of sunshine in the 
British Isles (after Mr. H. N. Dixon), a very interesting 
coincidence can be traced. The sunniest part of Britain, 
which possesses from 1600 to 1700 hours of sunshine 
in the year, includes very nearly all the habitats of 
these rare Spanish plants. The line of 1600 hours of 
sunshine cuts off Beachy Head, part of Dorset, about 
two-thirds of the Isle of Wight, and a considerable 
portion of south-west Cornwall and Devonshire ; it then 
curves up to the north so as to take in a little of south- 
west Wales, and fringes the southern Irish coastline. 
The Irish observations seem to have been insufficient, 
but it seems that the curious sporadic and irregular dis- 
tribution of these peculiar southerners really does more 
or less coincide with a sunshine amount of between 
1600 and 1700 hours per year, 
This part of England seems to have escaped the ice 
of the glacial period, and it is quite likely that the 
arbutus and asparagus are relicts of the first warm and 
dry interglacial period. But of course this is a question 
which requires much more detailed evidence. 
There is yet another little group, the Blue-eyed grass, 
Eriocaulon, and Spiranthes Romanzofiana, about which 
there has been plenty of speculation and discussion, 
The last grows in Kamschatka, and also in Bantry Bay, 
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