The area surrounding Willowyards and its whisky bond are characterised by harmless but distinctive black staining that covers living and non-living surfaces to varying degrees.
In 1872 the French pharmacist Antonin Baudoin noted that a black, sooty growth, rare elsewhere, was to be found growing profusely on the walls and roof tiles of buildings near distilleries in Cognac, France
The research that first led to the scientific identification of the unusual organism causing these black and velvety encrustation was partly carried out using samples from the Willowyard site. Here it favours areas with extreme temperature variations. It also covers the bark of trees and yet it does not seem to reduce their growth as witnessed by notable healthy tree specimens that pre-date the whisky bond. It is a preferred food for snails and slugs.
The organism causing what is commonly known as 'Wharehouse Staining', is the fungus, Baudoinia compniacensis which is harmless and feeds upon the 'Angels's Share' of alcohol from the whisky barrels. Its closest relatives are rock-inhabiting species known only from the Antarctic.