Rare plant of the month – June 2018

Athyrium filix-femina ‘Acrocladon’ – a fern lost and found

The British Pteridological Society (BPS) is an eminent scientific society, involved in the study and research of ferns. Among them, are group of plantsmen also involved in work with fern cultivars. Julian Reed (National collection holder of Polypodium) is one of them and while talking about finding the stories of our rare plants, he suggested the extraordinary story behind Athyrium filix-femina ‘Acrocladon’.

We know through our research at Plant Heritage on the Threatened Plants Project (recognising and recording missing or lost cultivars), just how many ‘lost’ plants are possibly still  growing unrecorded in gardens in the UK. When we find locations of live specimens it is a great feeling. Julian sent us this lovely story of determination and refusal to believe something had gone forever.

The BPS itself was founded in the Lake District in 1891, so the earlier date of the discovery of  this rare fern cultivar makes the story all the more pertinent:

Athyrium filix-femina ‘Acrocladon’ re-found. This fascinating fern, completely different in form to the lady fern we see growing in woods and beside streams, was originally found in about 1863. Plantsman and fern expert Reginald Kaye, still had it in the 1960s but I could not find any one who had seen it for many years.

A group of us in the Cultivar Group of the British Pteridological Society (BPS) visit gardens of old members looking for the lost varieties and up until last year I had been saying ‘Acrocladon’ was a such small grower that if neglected it would not survive.

However a friend, Steve Coleman was sure we would find it one day and that another friend, Alec Greening had heard of someone who had some ‘choice lady ferns’. After several attempts to contact him, this lovely guy – Ian Unsworth, contacted us. He confirmed that he did indeed have ‘Acrocladon’ and this spring (2018) let us have a couple of crowns. Once it has settled down and produced a new crown in time, one will be sent to the National Collection of Athyrium filix-femina.

Not only is this the same clone that Reginald Kaye had in the 60’s, it is amazingly now more than 150 years old!

E.J. Lowe wrote about Athyrium filix femina ‘Acrocladon’ in his book, ‘Our Native Ferns of 1867’

This variety is worthy of the title ‘Queen of Lady Ferns’ indeed its exquisite foliage is unequalled in the whole range of British botany, and, at the present time, it is at once the rarest and most remarkable of the British filices. Hitherto barren, plants have only been obtained by division, a slow process, which in eight years has not yielded as many plants. There is, therefore, no immediate likelihood that this much-coveted prize will become generally distributed. Indeed, so slowly has this charming Fern been increased, that the discoverer, Mr. C. Monkman, of Malton, has had to exercise seven years’ patience before obtaining a specimen for his own collection’.

The original plant was found by Mr. Monkman growing by a road-side on the moor track between Byland and Rivaulx Abbeys, in Yorkshire.

There were a few other Lady Ferns in company, all of which were quite normal and, although various botanists have carefully searched the station many times, no second plant of ‘Acrocladon’ has been met with, nor has even a slight divergence from the normal form of Athyrium been found. The discoverer presented his plant to Mr. A. Clapham, of Scarborough, in whose possession it has since remained. In 1863 that gentleman could boast of a plant (the original one) fully two feet high, and as much in diameter, a mass of the most exquisite foliage’.

This height is exceptional as they are normally only 12 inches/30cm, so we suspect it was grown under glass like many of the fern growers did in that day.

It is considered by Julian and others, that since this time other ferns, such as Athyrium filix-femina ‘Plumosum Drueryi’ have probably taken the crown of ‘Queen of the Athyriums’…

Image and text from E J Lowe’s book:


The pictures are of fronds from late autumn. Spores were found and young plants are developing now but whether true to type is another question. Hopefully we will be able to re grow the cultivars that had been grown from it originally

Julian Reed, is Plant Heritage, National Collection Holder of Polypodium (hardy cultivars) and member of the British Pteridological Society.

We are grateful to Alec Greening, Steve Colman, and Ian Unsworth for allowing us to use their shared story.

British Pteridological Society website: www.ebps.org.uk 


One thought on “Rare plant of the month – June 2018

  1. Judy Barker

    What a lovely story of plant hunting in reverse, and the joy of sharing plants and knowledge to ensure their survival Judy Barker

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