Irish Endemic Hawkweeds (Hieracium)
Staff: Tim Rich
The National Parks and Wildlife Service of the Republic of Ireland commissioned a review of the status of the seven hawkweed (Hieracium) species endemic to Ireland: H. argentatum, H. basalticola, H. hartii, H. hesperium, H. hibernicum, H. scullyi and H. sparsifrons. Only one species is widespread, the remainder being rare or very rare. Hieracium is a genus in which species are difficult to identify and require expert survey. The project involved compilation and review of existing data, and field work from 2006–2008 to assess their current population sizes and determines their needs for conservation. Live material of some species was also collected for seed banks and cultivation in the National Botanic Garden, Glasnevin. The data are currently being published.
Hieracium argentatum is endemic to Kerry, 870 plants were found in seven sites, and it was not refound in five sites. It mainly occurs on rocky riversides or open rocks, usually on sandstone, in open vegetation. The extant populations currently appear quite healthy, and under relatively low threat.
Hieracium basalticola is widespread in the west and north of Ireland from Clare to Antrim, where at least 37 sites have been recorded. In the 23 historic sites visited, it was refound in 16 sites (70%) and a total population of at least 3,950 plants estimated. Seven new sites were found. It is likely that there are significantly more plants in unsurveyed areas. It was not refound in six historical sites, and is probably extinct in four of these.
Hieracium hartii is endemic to Donegal. It has been regarded as extinct but was rediscovered on Slieve League, in its only locality. The population is estimated to be about 50 plants on mountain cliffs associated with other arctic-alpine species. Records for Ben Bulben and the Ox Mountains are errors.
The taxonomic status of Hieracium hesperium, reputedly endemic to Donegal, has been reviewed, and it may not merit recognition as a distinct species.
Hieracium hibernicum is endemic to Donegal and Down, 41 plants were rediscovered on the Owengarve River, West Donegal, but it was not refound on the Laghy River, East Donegal or the Mourne Mountains, Co. Down. It is a rare species of rocks by rivers in places inaccessible to grazing animals.
Hieracium scullyi is endemic to Kerry, 103 plants were found in five populations on the Roughty River, and 107 plants in a new site in the Black Valley. It appears to have gone from Morley’s Bridge. It is a species of acidic sandstone rock crevices on rocky riverbanks in the zone between winter floods and summer flows, and also on the associated rocks above, and on rocks by lakes. It also occurs on mortar on bridges. It occurs in open vegetation, and is probably susceptible to grazing.
Hieracium sparsifrons is endemic to Kerry, 203 plants were found in the five historical sites and two new sites on the Roughty, Clydagh and Slaheny Rivers. It is a species of open vegetation in acidic sandstone rock crevices on rocky riverbanks in the zone between winter floods and summer flows, and also on associated rocks above. It also occurs on mortar on bridges.