Lichens and Litmus Dyes

[J.Morley at rbgkew.org.uk]

I have been asked if I have any information on the history 
of lichen use in the production of litmus, particularly 
from East Africa.

There is one paper, by Peter Greenway, in the East African 
Agricultural Journal 8(1): 46-7, 1942, and some other 
general information from about the same time.

Does anyone have anything that they can add to this, 
particularly relating to the trade that had evolved between 
Africa and Europe?

Many thanks

James Morley
Centre for Economic Botany
Royal Botanic Gardens, Kew

J.Morley at rbgkew.org.uk
http://www.rbgkew.org.uk/ceb/