hair (and it is still sold in the best chemist shops as an ingredient in anti-
dandruff shampoos). The only unambiguously folk record traced, however,
is a treatment in Ireland for sore eyes: in Leitrim the ‘greyish mossy substance’
growing on the blackthorn trunks is presumably U.subfloridana Stirton,
which commonly grows on the twigs of that tree. It was mixed with tobacco
and butter, boiled and then cooled before being applied as a lotion.^27
Perhaps an Usnea species was also the mysterious ‘brighten’, a lichen
known by that name in the New Forest in Hampshire and recommended
there for use on weak eyes at one time.^28
PELTIGERACEAE
Peltigera aphthosa (Linnaeus) Willdenow
sea-green lichen
northern and southern temperate and alpine zones
As its specific name indicates, the widespread and formerly more common
Peltigera aphthosa was regarded as specific for that fungus infection of the
mouth and tongue, especially found in children, known to learned medicine
as aphthae and colloquially as ‘the thrush’. The sole evidence traced of this
lichen’s use in folk medicine is provided by Withering, according to whom
‘the common people’ in his day made an infusion of it in milk and gave it to
children afflicted with that complaint. He added that in large doses it caused
purging and vomiting and was effective against intestinal worms.^29
Peltigera canina (Linnaeus) Willdenow, in the broad sense
dog lichen, liverwort lichen, ash-coloured liverwort
cosmopolitan
With fruit-bodies resembling dogs’ teeth,Peltigera caninawas long regarded
as a supposedly certain specific antidote to the bite of a rabid dog or of result-
ing hydrophobia. The lichen is said to have been still in widespread use for that
in the early nineteenth century in the Snowdonia area of Caernarvonshire,
where it was dried, reduced to a black powder and mixed with black pepper.^30
LOBARIACEAE
Lobaria pulmonaria (Linnaeus) Hoffman
tree lungwort, lungs of oak, lung lichen
nearly circumboreal in northern hemisphere, south to Korea, Mexico
and Canaries; South Africa
Afrequent species on old oaks,Lobaria pulmonariawas recommended in the
42 Usnea