Pulsatilla vulgaris (L.) Mill. - Plantlife

Of the 10 vice-counties with surviving populations, seven only have single colonies.
Bedfordshire and East Gloucestershire have the most with 4 and 5 populations respectively.
Half the English populations support less than 100 plants, including one site (Ledsham, Midwest
Yorkshire) with a single individual (known since 1984). Only five sites (28%) support in
excess of 1000 plants (Fig 4a). Although total population sizes are difficult to estimate, recent
counts on these sites suggest the following totals: 20,000 at Barnack Hill and Holes, 75,000 at
Barnsley Wold, 5,000 at Barton Hills, 1,000 at Knocking Hoe and 60,000 at Therfield Heath
(Tarpey, 1999; see Annex 2 for details). These five sites account for 99.3% of the total British
population. Of the eighteen surviving populations 4 appear to be declining and are threatened
with extinction, 9 are stable and 5 appear to be increasing due to improvements in grazing
regimes (Table 3; see Annex 2 for details).
Figure 3 – The hectad
distribution of Pulsatilla
vulgaris in Britain and Ireland.
Solid black circles are hectads
where P. vulgaris has been
recorded since 2000; solid grey
circles, recorded 1987-1999;
open circles, recorded before
1987; X, introduced.
Historical losses appear to have been high in all vice-counties especially East Gloucestershire,
South Lincolnshire and Berkshire where 77%, 89% and 92% of populations have gone extinct
(Table 2). The rate of loss appears to have been increased consistently since 1750 from around
1.8 populations per decade to 6.0 since 1950 (Fig. 4b) although these figures presumably
underestimate rates for earlier periods as fewer ‘extinction events’ are likely to have been
detected by eighteenth century botanists (as fewer populations were then known).
Consequently the total number of populations has displayed a consistent downward trend (Fig.
4c). However, since 1960, the first period when we have detailed information on the size of
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