Ed Dolphin writes for the Sid Valley Biodiversity Group.

It has been an awfully wet spring, but one plant that has loved the deluge is the Hart’s Tongue Fern that lives at the edges of our woodland and on most of our banked hedges. They are evergreen and the lolling green fronds are with us all year, but the new season’s growth is emerging in the typical unfurling way that ferns have of putting out new fronds.

It is easy to see how these primitive plants gained their common name, particularly as they uncurl the green straplike fronds from the top of their rhizome which will be wedged into any damp crevice that can be found, including in local walls and the bark of old trees.

Hart’s Tongue is a member of a family of small ferns called Spleenworts, plants that will treat your spleen problems. Medieval herbalists believed the plants could be used as a treatment for depression caused by an excess of black bile from the spleen.

The great botanist Carl Linnaeus gave Hart’s Tongue the Latin name Asplenium scolopendrium, spleenwort like a centipede. Unlike with the proven herbal remedy of St John’s Wort, there is no good evidence for Spleenwort helping with depression, but the pattern of linear spore producing sori spreading on either side of the midrib on the underside of the fronds is reminiscent of a centipede.

As with all ferns, Hart’s Tongue has a two stage life cycle. The linear sori on the back of the frond release thousands of tiny spores in the summer. If one of these lands in a suitable spot it will grow into a tiny plant called a prothallus. This has male and female organs that produce gametes. The male gamete has to swim to find a female gamete and fuse to form an embryo. This will grow into the spore producing fern and the cycle begins again.

We have several other members of the Spleenwort family around the town. They are small ferns with feathery fronds and usually live in cracks in limestone cliffs. The old walls in parts of the town that have lime mortar rather than Portland cement will do as cliff for Black and Maidenhair Spleenwort and Wall Rue. In his 19th century book The Ferns of Sidmouth, Peter Orlando Hutchinson also listed Sea Spleenwort and Rustyback, but the Biodiversity Group plant survey hasn’t found them, yet.