The Summary page includes information from the New Atlas of the British & Irish Flora, which should be consulted for further details.
The map on the Summary page shows the distribution of the species in Britain and Ireland and is derived from the NBN Gateway. It shows all records from the Vascular Plant Database, hosted at the Biological Records Centre and made available via the NBN Gateway on behalf of the Botanical Society of the British Isles (BSBI). The records are contributed largely by members of the BSBI. They are plotted in 10 × 10-km Ordnance Survey grid squares (‘hectads’) and are shown as one of three symbols which denote the date of the latest record – dark squares (after 1986), pale squares (1970–1986) and pale circles (before 1970). All records are plotted regardless of native status.
This gives a brief description of the habitat of the species and ends with a statement of its altitudinal range. ‘Lowland’ indicates plants which are not found above 300 m.
This identifies plants which are
Native: species which colonised Britain or Ireland without human intervention, or evolved here
Archaeophyte: species which were brought to our area by human activities, whether intentionally or unintentionally, and became established members of the flora before 1500 ad
Neophyte: species which were brought to our area by human activities, whether intentionally or unintentionally, and became established members of the flora after 1500 ad
Casual: species which are brought to our area by human activities, whether intentionally or unintentionally, but do not persist in the wild (or do not persist for more than five years) and so are dependent on constant re-introduction.
The allocation of species to these categories is sometimes doubtful.
This gives a brief interpretation of trends in the distribution of the species – whether the range (total geographical spread) and frequency (proportion of hectads within that area) is stable, increasing or decreasing. These comments relate to the hectad scale of the maps. The dates when neophytes were first introduced into cultivation in our area and the date when they were first recorded from the wild may be given in this paragraph.
This summarises the distribution in the northern hemisphere of native species and some introduced species according to the classification proposed by Preston & Hill (1997). The native range is summarised for the other introduced species.
Preston, C. D., Pearman, D. A. & Dines, T. D. (ed.) (2002) New Atlas of the British and Irish flora. Oxford: Oxford University Press.
Preston, C. D. & Hill, M. O. (1997) The geographical relationships of British and Irish vascular plants. Botanical Journal of the Linnean Society 124: 1-120.