John Cameron 
Gaelic Names of Plants (Scottish, Irish, and Manx) [PDF ebook] 
Collected and Arranged in Scientific Order, With Notes on Their Etymology, Uses, Plant Superstitions, Etc;, Among the Celts, With Copious Gaelic, English, and Scientific Indices

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. It was absolutely essential that the existing Gaelic names should be assigned correctly. The difficulty of the ordinary botanical student was here reversed: he has the plant but cannot tell the name – here the name existed, but the plant required to be found to which the name applied. Again, names had been altered from their original form by transcription and pronunciation it became a matter of difficulty to determine the root word. However, the recent progress of philology, the knowledge of the laws that govern the modifications of words in the brotherhood of European languages, when applied to these names, rendered the explanation given not altogether improbable. Celts named plants often from their uses; their appearance; their habitats; their superstitious associations, &c. The knowledge of this habit of naming was the key that opened many a difficulty. For the sake of comparison a number of Welsh names is given, selected from the oldest list of names obtainable – those appended to Gerard’s 'herbalist, ’ I 597.