realized I forgot to identify myself in the above post...

here are some other references for the old herbal lore:

Cockayne, O. (ed.). 1864–66. Leechdoms, Wortcunning, and Starcraft of Early England

Grattan, J. H. C. and C. Singer. 1952. Anglo-Saxon Magic and Medicine Illustrated Specially from the Semi-Pagan Text 'Lacnunga', Publications of the Wellcome Historical Medical Museum, new series 3 (London: Oxford University Press). Edition and translation.

The book I was originally thinking of was "The Old English Herbals" by Eleanour Sophy Sinclair Rohde (1881–1950), who was a British gardener, garden historian, and horticultural writer. She designed the herb garden for Lullingstone Castle in Kent, England. She wrote this book in 1922. I highly recommend it if you are interested in the subject and apparently it has been reprinted.