Another speciality of that same central belt is the valuing ofPrimula vul-
garis (primrose) as a treatment for jaundice. Yet that is the part of Ireland
where that plant is at its most scarce, on account of the high lime content of
the soils, and yet, paradoxically, where its sister species,P. v e ris (cowslip),
which is preferred to the other as a jaundice cure elsewhere, attains its great-
est Irish plenty. No less difficult to account for is the marked concentration
along that country’s western coast of the records for the employment of
Taraxacum officinale (dandelion) for heart trouble as well as for tuberculosis.
Equally hard to explain is the restriction to the three adjacent border coun-
ties of Cavan, Monaghan and Louth of the records for boiling ‘thistles’
(apparently Silybum marianum) in milk as a remedy for whooping cough.
More unexpected than any of those, however, is the chequer-board pat-
tern revealed by studying in tandem the distributions of their recorded use in
folk medicine of two herbs not previously thought of as being in any way
associated. Though these are alike in having foliage of a kind that botanists
term ‘fleshy’, one of them,Umbilicus rupestris (navelwort), is unquestionably
a native whereas the other,Sempervivum tectorum (house-leek), is equally
unquestionably an ancient introduction, for it is apparently always sterile
and is believed to have originated in central Europe, perhaps as a hybrid; it
has also been widely known by an alternative name, sengreen, that appears to
be Anglo-Saxon in origin. When the overall herbal distributions of these two
are compared in detail, they turn out to be mirror images of one another:
where one county has seemingly specialised in the Umbilicus species, a neigh-
bour of that has seemingly chosen the Sempervivum—and presumably
instead. Because the Umbilicus can flourish only in the wetter climate of the
western half of the British Isles, there was a vacant niche in the east for a herb
of vaguely similar character (though not appearance) and credited with sim-
ilar healing properties. But the Sempervivum had the edge in also being cred-
ited with magico-religious power, and after its introduction from the Euro-
pean mainland (presumably by post-Roman Germanic immigrants) it was
evidently taken far and wide into the territory of the Umbilicus.The age-old
attachment to the Umbilicus species in the west, though, must have been suf-
ficiently deep to prevent a total replacement occurring. Closer analysis may
one day demonstrate that it has been in those parts of Ireland where English
penetration has been longest and most pronounced that the Sempervivum
attained its principal distribution.
The greater completeness of the Irish records geographically and the
greater scale on which reliance on folk medicinal herbs has persisted in that
346 Distribution Patterns