Despite its Latin and English names being huge the Least Adder’s-tongue fern (Ophioglossum lusitanicum) is one of our Islands’ smaller specialities.

The Least Adder’s-tongue fern is an annual winter fern which is nationally rare (growing only on Scilly and in the Channel Islands). It boasts tiny leaves and when “in-bloom” a spear shaped blade.

In Scilly the Least Adder’s-tongue fern has been recorded growing in a number of locations but is predominantly found on Wingletang Down on St Agnes.

Wingletang is one of the 24 Sites of Special Scientific Interest (SSSI) looked after by the Isles of Scilly Wildlife Trust and has been cited as such under the 1981 Wildlife & Countryside Act since the 15th December 1986 - that’s more than 30 years!

The reasons for this designation are numerous but the Least Adder’s-tongue is probably the smallest and most interesting. Ophioglossum ferns have the highest chromosome count of any known living organism; to put that into perspective, humans normally have 46 chromosomes, Ophioglossum ferns have 1260!

Wingletang has slowly but surely become dominated by Gorse. This once rich and varied maritime heathland previously supported larger populations of the smaller rare plants but they simply cannot survive within the thick mat of prickly vegetation. 

In early 2015 there was an area of 5.06 hectares (12.5 acres) of dense Gorse on Wingletang

In 2015 the Isles of Scilly Wildlife Trust Ranger Team started a programme of work with the aim of reducing the amount of Gorse on Wingletang; this programme included cutting firebreaks and removing sections of Gorse to encourage and promote regeneration of heather and grassland areas (habitats preferred by our smaller, rarer plant species) and prevent Gorse from further encroaching on areas where we know Least Adder’s-tongue is growing.

During 2015/16 the Rangers cut 0.75 hectares of Gorse on Wingletang; in 2016/17 the Rangers maintained that clearance and added another .75 hectares (for those of you into Cricket that’s an area the size of Lords).