19 SEPTEMBER 1970, Page 26

Nature notes

Sir: I read with particular pleasure Mr Christopher Booker's comments on natural phenomena which from time to time appear in your paper. I too have noticed the pro- liferation of the Yellow Toad Flax in this part of the world. Round here the folk say that this portends a harsh winter to come.

But I wonder, is Mr Booker right to refer (12 September) to the sloe as 'purple'? Perhaps it is a defect in my own vision but personally I would describe it as being of a blue nature—albeit, dark: My dictionary would seem to confirm my view, describing the sloe as being bluish-black. The Scottish poet David Kemp (1745-1820) would also seem to agree with me on this point, for he describes 'The humble sloe, so bonny and so blue.'