Here is another example of moorland foliage that Sir Arthur Conan Doyle would have been familiar with, but that I have never seen here in America. The Hart’s-Tongue Fern is mentioned several times in The Hound of the Baskervilles, one of The Greatest Adventures of Sherlock Holmes. I found this really neat website, Woodland Trust, with pictures of the fern as well as some interesting background on the fern.
According to Woodland Trust, the Hart’s-Tongue Fern is a sign of ancient woodland and may indicate that its habitat is unique. Some of the United Kingdom’s ancient woodlands date back to the 1600s. Woodland Trust has another full article about what ancient woodlands are and how to spot them.
Dr Watson mentions in The Hound of the Baskervilles that there are old stone huts on the moor, indicating a thriving, ancient civilization that lived there once. One of the characters, Dr Mortimer, studies those ancient people by excavating near the ruins and recovering skeletons and other artifacts. Holmes himself makes use of the ruins when he needs a place to hide and watch the villain. It is safe to say, then, that the moor, as Dr Watson described it, is ancient.