Pteridomania

Pteridomania or Fern-Fever was a craze for ferns. Victorian decorative arts presented the fern motif in pottery, glass, metal, textiles, wood, printed paper, and sculpture, with ferns "appearing on everything from christening presents to gravestones and memorials".

Pteridomania, meaning Fern Madness or Fern Craze, a compound of Pteridophytes and mania, was coined in 1855 by Charles Kingsley in his book Glaucus, or the Wonders of the Shore:

Your daughters, perhaps, have been seized with the prevailing 'Pteridomania'...and wrangling over unpronounceable names of species (which seem different in each new Fern-book that they buy)...and yet you cannot deny that they find enjoyment in it, and are more active, more cheerful, more self-forgetful over it, than they would have been over novels and gossip, crochet and Berlin-wool.

According to one author:

Although the main period of popularity of ferns as a decorative motif extended from the 1850s until the 1890s, the interest in ferns had really begun in the late 1830s when the British countryside attracted increasing numbers of amateur and professional botanists. New discoveries were published in periodicals, particularly The Phytologist: a popular botanical miscellany, which first appeared in 1844. Ferns proved to be a particularly fruitful group of plants for new records because they had been studied less than flowering plants. Also, ferns were most diverse and abundant in the wilder, wetter, western and northern parts of Britain which were becoming more accessible through the development of better roads and the railway.

The collection of ferns drew enthusiasts from different social classes and it is said that "even the farm labourer or miner could have a collection of British ferns which he had collected in the wild and a common interest sometimes brought people of very different social backgrounds together."

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Wikipedia