Sentence:  He went on foot across the wilder recesses of the park, where slimy streams of green moisture, exuding from decayed holes caused by old amputations, ran down the bark of the oaks and elms, the rind below being coated with a <WSD>lichenous</WSD> wash as green as emerald. 
Meaning of the word marked with <WSD> tags:  Composed of lichen.