The Magnesian
Limestone extends as a narrow strip northwards from Nottingham to
Durham which is nowhere more than a few kilometres wide. It is
entirely lowland in altitude and reaches the coast in Durham. Lying
as it does between the Jurassic limestones to the east and south
and the Carboniferous Limestone to the west and north, the
Mag-nesian Limestone has grasslands which show intermediate
characteristics in floristics. It is sufficiently far south to
support southern grassland dominants such as Brachypodium pinnatum
and Zerna erecta, and characteristic species such as Anemone
Pulsatilla (formerly), Linum anglicum, Blackstonia perfoliata,
Inula conyza and Carex ericetorum; while some of the exposures are
far enough north to have northern plants such as Sesleria albicans
and Epipactis atrorubens.
In general
floristics, the Magnesian Limestone grasslands have a good deal in
common with those of the Jurassic limestones. They are now
extremely limited in area, since many of the original outcrops of
this rock formation have been quarried virtually out of existence.
The other magnesium-rich limestones of Scotland are best regarded
as belonging to the upland group of ecosystems, and the best known
exposures the Durness Limestone, are dealt with in Chapter
9.
