The hybrid was first discovered by
George Lawson in July 1845 at
Gullane,
East Lothian,
Scotland, and two voucher specimens were deposited in the
herbarium of William Gardiner,
Dundee. Following Gardiner's death in 1852 the specimens were transferred as part of a bequest to the
British Museum, and shortly afterward (
ca. 1854) loaned to German botanist
Friedrich W. Schultz, who described them as a new variety of
Helosciadium nodiflorum, var.
longipedunculatum. The variety was later (1906) described in further detail by Harry J. Riddelsdell and Edumund G. Baker, who examined a number of specimens from the original Gullane locality, as well as additional specimens from
Duddingston Loch,
Edinburgh, Scotland. While Riddelsdell did not consider var.
longipedunuclatum to be of hybrid origin, during the course of the 20th century a number of eminent botanists (e.g.
Werner Rothmaler,
Clive Stace) suggested that it was the hybrid between
H. repens and
H. nodiflorum. In 2014, plants matching
H. nodiflorum var.
longipedunculatum were collected at
Port Meadow,
Oxfordshire,
England and a molecular analysis confirmed it as the hybrid
H. repens ×
H. nodiflorum. The original specimens are still housed in the
Natural History Museum, London, under voucher number BM001144095, and the one situated to the left has been designated as the
lectotype. == Description ==