Helen Seal, Alpine and Woodland Supervisor
Cambridge University Botanic Garden
In the Bog Garden some years back an elderly visitor asked me to photograph him next to the Royal Fern, the Osmunda regalis. He’d been photographed next to it before, as an undergraduate and it had happy associations. A 60 year-old fern? This called for some investigation.
The garden’s enormous data base records the fern in that location in 1978, but the 1947 edition of the 1922 garden guide by Director Gilbert-Carter actually includes a photo of this large Osmunda in the same place, though it was then known as the Water Garden. The 1850 garden catalogue of Hardy Plants by Curator Murray lists it, as does Curator Donn’s 1811 catalogue of the former Botanic Garden in the Downing site area. This specimen could well be over 200 years old! I now know this longevity is characteristic: as long as its environment stays moist and boggy, Osmunda regalis keeps on growing for centuries. Fossil records apparently show it unchanged for 180 million years.
I love this living history, but I also love the plant itself. In winter all that’s above ground is a circle of dark fibrous mounds of rhizomes, a hard sponge with black spikes of old frond bases. In spring tufts of woolly-coated crosiers begin unfurling, and we edge the path with hazel branches to contain the coming exuberant growth. By the end of June each frond is over 2 metres tall and the clumps fountain over 3 metres wide, arching over the water of the bog. Each frond is like a long flexing spine with pairs of soft green ribs, except some of these pinnae (the leaflets of ferns) morph halfway into rusty-brown branching structures bearing the clusters of sponagnia (the spore sacs). These explain its former common name of the Flowering Fern – confusing as ferns don’t have flowers, propagating themselves over two generations, starting with spores.
Osmunda regalis can still be found in the wild, in the wetter, milder parts of Britain, and in Europe, but I’m delighted this magnificent old specimen is part of my dry east England workscape.