How did the Tunbridge filmy-fern get its name?

Hymenophyllum tunbrigense the Tunbridge filmy fern a species that grows mainly in the temperate rain forests of western Ireland, west Wales, south-west England and I believe in the southern states of the US. The town of Tunbridge Wells is in Kent (SE England) where the climate would probably be too dry and cold in the winter for this plant to thrive. In spite of its southerly location Kent is one the coldest places in England during the winter due to its distance from the Atlantic gulf stream. The same ocean current which provides the mild damp conditions in Ireland, Wales and SW England in which this plant thrives.