Pteridomania and an obsession with mutants

Thursday's Guardian Country Diary describes a fragment of mature old woodland at Wolsingham in Weardale whose fallen, decaying trees support a wealth of wildlife, including ...

..... this rather lovely epiphytic polypody fern that was attached to an oak branch that had been torn off by the gales. The golden structures on the underside are the sporangia, ripe and releasing spores. You can read about the full life cycle of ferns by clicking here and see some more close-up and microscope pictures of the sporangia by clicking here.



Picture by Helen Allingham, originally published in the Illustrated London News July 1871
http://en.wikipedia.org/wiki/File:Pteridomania.jpg

The golden age of fern popularity was in Victorian times, during a period that has come to be known as Pteridomania. Then the obsession with collecting and growing these plants reached an all-time high, so much so that the population sizes of some native ferns (like holly fern in Teesdale and all the filmy ferns) were reduced to the point where they are now endangered species in our flora. The ladies in the image above are well equipped for digging up choice ferms, although brambles must have played havoc with those dresses.

Advert from Choice British Ferns: Their Varieties and Culture by Charles T Druery F.L.S.(late 19th. century).

Commercial nurseries like W. andJ Birkenhead made a good living out of selling ferns, club-mosses and selaginellas to those who couldn't get out into the countryside to dig them up. The fern craze generated a wealth of popular and scientific literature on these plants, with books like .....

British Ferns and their Allies: comprising the Ferns, Club-mosses, Pepperworts and Horsetails by Thomas Moore F.L.S., F.H.S. (1881)

...... Thomas Moore's British Ferns and their Allies, which described them and told readers where to find them, as well as providing detailed advice on how to grow and propagate them. 

Remarkably, pteridomania wasn't confined to adults; there were fern books for children, like Francis Heath's Fairy Plants: a Fern Book for Children. In his preface he wrote "There is probably no part of the beautiful realm of Botany capable of offering so much fascination for young people as that which is dominated, so to speak, by ferns; and it is because I can conceive of no branch of a delightful subject so likely to incalcate ideas of gracefulness and to instil elevating, indeed ennobling, thoughts, that I have written a fern book for children".

Decorated initial letter from Fairy Plants: a Fern Book for Children by Francis Heath

I suspect that the thoughts of most 21st. century 12 year-olds, unwrapping such a book given as a present, would be far from ennobling. 

So why did ferns become so popular?

Illustration from Ferns and Fern Culture by J. Birkenhead F.R.H.S. (1897)

One reason was they did well as house plants in shady Victorian drawing rooms dimly lit my gas lamps, especially if they were grown in the humid confines of Wardian cases, like the ornate examples above.

Illustration from Ferns and Fern Culture by J. Birkenhead F.R.H.S. (1897)

Perhaps the ultimate expression of Pteridomaniacal one-upmanship was to construct a shady, rocky fernery in your garden.

Illustration from the Fern World by Francis George Heath (1879)

This, perhaps, was the ideal - a reconstruction of that shady woodland stream where you originally stole your plants from. The picture caption gives some idea of the effect they were hoping to achieve: 'We look with wonder upon a fairy, dreamy scene of clustering ferny forms in fascinating association with mossy rocks an flowing water'.

Another reason was that the elaborate fractal geometry of fern fronds appealed to Victorian arts and craft taste, in jewellery such as this brooch, and in ....



.... garden furniture. The flatness of a fern frond lent itself to recreation in cast iron or in applied patterns on decorative objects.

The fern craze died out in 1914, but not before it had produced one more fascinating botanical obsession, with monstrosities.



Illustration from Ferns of Great Britain and their Allies the Club-mosses, Pepperworts and Horsetails by Anne Pratt (1855)

This is the typical 'wild type' hart's tongue fern Phyllitis scolopendrium.....

Illustration from Choice British Ferns: Their Varieties and Culture by Charles T Druery F.L.S.(late 19th. century).

....... and these are some of the multitude on hart's tongue mutants that Victorian fern-fanciers raised and which many prized as the gems in their collections. Similarly, .....

...... this is the wild type polypody Polypodium vulgare ....

Illustration from Choice British Ferns: Their Varieties and Culture by Charles T Druery F.L.S.(late 19th. century).

...... and these are some of the many mutants of the same species that were cultivated, most unrecognisable as polypody.

Although Gregor Mendel published his experiments in 1865 his discoveries on inheritance remained unrecognised until 1900, so the Victorians knew nothing about the genetic mechanisms that generated such mutants.It would be more than a century before the science of plant developmental genetics would reveal the ways in which simple gene mutations can generate such spectacular variations in leaf developmental pathways.