to seven widely separated Irish counties and in Britain only to three of its
westernmost extremities (Cornwall, Pembrokeshire, Scotland’s Outer Heb-
rides)? Though no other use exhibits this pattern with such precision, there
are several more that broadly approximate to it: the pondweeds Potamogeton
natans and/or P. polygonifolius for burns,Linum catharticum (fairy flax) for
menstrual irregularity and species ofArctium (burdock) as a purifying tonic.
Other plants such as Sorbus aucuparia (rowan),Myrica gale (bog-myrtle),
Rumex acetosa (common sorrel) and the Lycopodiaceae (clubmosses) are
broadly ‘Celtic fringe’ across the full range of their herbal functions, but
except in the case ofR. acetosa those are ones restricted to Ireland and north
and west Britain already by habitat and climate requirements.
Neither environmental determinants nor cultural links, however, seem
capable of explaining why both Wales and the south-west of England stand
well apart in certain respects not only from the rest of the ‘Celtic fringe’ but
from other parts of the British Isles as a whole. Apparently peculiar to Corn-
wall and Devon, for example, has been the very extensive drinking of ‘organ
tea’ made from Mentha pulegium (pennyroyal), partly just as a refreshment
but mostly to clear the nasal and bronchial passages whenever colds or related
complaints occur. Though a plant rather specialised in its habitat demands,
this species of mint formerly grew naturally in much of lowland England, so
it is hard to understand how it came to be preferred over other members of
the mint family that have a similar therapeutic property so widely and so
persistently in just that one corner of the country. No less hard to explain is
the seeming near-restriction of the herbal use ofAnagallis arvensis (scarlet
pimpernel), a plant far more common and generally distributed than M.
pulegium,to that same corner of England (and to some extent the neigh-
bouring parts of Wales as well). Even more inexplicable is the uniquely wide
range of uses to which the multitudinous microspecies ofRubus fruticosus
(blackberry) have been put in that region—one of them, the application of
the leaves to skin complaints, seemingly unrecorded anywhere else. Yet those
plants are no more nor less ubiquitous in the West Country than in most
other lowland areas of England, Wales and Ireland, nor is there any evidence
that any of the microspecies special to that region are particularly endowed
with properties that make them more rewarding for herbal purposes than
elsewhere. Why, too, is it virtually only on the stony beaches of England’s
south-west that another widespread plant,Glaucium flavum (yellow horned-
poppy), has been sought out for the putative healing power of its latex? Are
what we confronted with in cases such as these the relics of uses that origi-
340 Distribution Patterns