A new species of dandelion has been discovered growing on one of the remotest islands in the Outer Hebrides.
The plant is only known from the Isle of Hirta, in the archipelago of St Kilda, where it may be endemic and may be among the rarest plants in Scotland’s flora. It is thought that the plant could have been brought to St Kilda by birds or Vikings, and Iceland is thought to be the most likely source.
Seeds from four plants were collected two years ago by Jim McIntosh* when he joined a group of botanists from the Royal Botanic Garden Edinburgh (RBGE), on a sailing trip to the island of Hirta to carry out a survey of higher plants and bryophytes.
The seeds have been successfully propagated at the RBGE nursery by horticulturist Natacha Frachon. It is the presence of unique hairy exterior bracts on the flower bud that led botanists to believe it is a new species of Asteraceae, the largest family of flowering plants. The St Kilda dandelion is also much smaller than the common species.
The newly discovered dandelion has been named Taraxacum pankhurstianum for Richard Pankhurst, a retired staff member at RBGE who still carries out research work. He was involved in its culture and has been interested in the taxonomy, distribution and the computer-assisted identification of Taraxacum for more than thirty years.
When Richard, who is the vice-county recorder for the Outer Hebrides, heard about the trip in June 2010 he asked Jim McIntosh to collect any Taraxacum seed he saw while on his journey. Jim* works for the Botanical Society of the British Isles as coordinator for Scotland.
Richard said it is an honour to have the dandelion named after him. He added: “St Kilda is known to have two endemic species of mice and a wren, and now we know it has a dandelion too.’’ The dandelion was named by Professor James Richards, of Hexham, Northumberland, who saw the species and recognised that it was new.
Taraxacum may be rare on St Kilda because it is eaten by animals including sheep and perhaps, some birds. Also, botanists tend to visit St Kilda outside the very short dandelion season, which may peak in May on the island.