Maps

Four maps are given in this section in the following order.

New Atlas (+updates) map at hectad resolution

The map shows the distribution of the species in Britain and Ireland and is derived from the NBN Gateway. It shows all records within the Vascular Plant Database hosted at the Biological Records Centre on behalf of the Botanical Society of the British Isles (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 squares (before 1970). All records are plotted regardless of native status.

BSBI Maps Scheme at hectad resolution

The map shows the distribution of the species in Britain and Ireland and is derived from records held by the BSBI. They are plotted in 10 × 10-km Ordnance Survey grid squares ('hectads') and are shown as one of six symbols which denote the date of the latest record - blue squares (after 2010), purple squares (2000-2009), orange squares (1987-1999), green squares (1970-1986), yellow squares (1930-1969) and magenta squares (before 1930).

All records are plotted regardless of native status.

BSBI Maps Scheme at tetrad resolution

The map shows the distribution of the species in Britain and Ireland and is derived from records held by the BSBI. They are plotted in 2 × 2-km Ordnance Survey grid squares ('tetrads').

All records are plotted regardless of native status.

Published New Atlas map

The map published in the New Atlas.  Records are mapped as one of the following symbols:

dark blue = present as a native between 1987 and 1999

blue = present as a native between 1970 and 1986, but not recorded as either a native or an introduction since then

pale blue = present as a native before 1970, but not recorded as either a native or an introduction since then, or records undated

red = present as an introduction between 1987 and 1999

pale red = present as an introduction between 1970 and 1986, but not recorded as either a native or an introduction since then

pink = present as an introduction before 1970, but not recorded as either a native or an introduction since then, or records undated