Two Potentillas occur among our common native plants, and
possess certain curative virtues (as popularly supposed), the
Silverweed and the Cinquefoil. They belong to the Rose tribe, and
grow abundantly on our roadsides, being useful as mild astringents.
The Potentilla anserina (Silverweed) is found, as its adjective
suggests, where geese are put to feed.
Country folk often call
it Cramp Weed: but it is more generally
known as Goose Tansy, or Goose Gray, because it is a spurious
Tansy, fit only for a goose; or, perhaps, because eaten by geese.
Other names for the herb are Silvery Cinquefoil, and Moorgrass. It
occurs especially on clay soils, being recognised by its pinnate
white silvery leaves, and its conspicuous golden flowers.
In Yorkshire the roots are known as moors, which boys dig up and
eat in the winter; whilst swine will also devour them greedily. They
have then a sweet taste like parsnips. In Scotland, also, they are
eaten roasted, or boiled; and sometimes, in hard seasons, 
when other provisions were scanty, these roots have been known to
support the inhabitants of certain islands for months together.
Both the roots and the leaves are mildly astringent; so that their
infusion helps to stay diarrhoea, and the fluxes of women; making
also with honey a useful gargle. The leaf is of an exquisitely
beautiful shape, and may be seen carved on the head of many an old
stall in Church, or Cathedral. By reason of its five leaflets, this
gives to the plant the title five leaf, or five fingered grass,
Pentedaktulon. Potentilla comes from the Latin potens, as
alluding to the medicinal virtues of the species.
In former days the Cinquefoil was much affected as a heraldic
device through the number of the leaflets answering to the five
senses of man; whilst the right to bear Cinquefoil was considered an
honourable distinction to him who had worthily mastered his senses,
and conquered his passions.
Silverweed tea is excellent to relieve cramps of the belly; and
compresses, wrung out of a hot decoction of the herb, may at the
same time be helpfully applied over the seat of the cramps. A potent
Anglo-Saxon charm against crampy bellyache was to wear a gold
ring with a Dolphin engraved on it, and bearing in Greek the mystic
words:--Theos keleuei mee keneoon ponois, God forbids the
pains of colic. This acted doubtless by mental suggestion, as in
the cure of warts. The knee-cap bone, or patella, of a sheep, known
locally as the cramp-bone, is worn in Northamptonshire for a like
purpose; also the application of a gold wedding ring (first wetted
with saliva, an ingredient in the holy salve of the Saxons), to a stye
threatened in an eyelid is often found to disperse the swelling; but in
this case  it may be, that a sulphocyanide of gold is formed
with the spittle, which promotes the cure by absorption.
A strong infusion, if used as a lotion, will check the bleeding of
piles, the ordinary infusion being meantime taken as a medicine.
The good people of Leicestershire were accustomed in bygone days
to prevent pitting by small-pox with the use of Silverweed
fomentations. A distilled water of the herb takes away freckles,
spots, pimples in the face, and sunburnings; whilst all parts of the
plant are found to contain tannin.
The Creeping Cinquefoil (Potentilla replans) grows also
abundantly on meadow banks, having astringent roots, which have
been used medicinally since the times of Hippocrates and
They were found to cure intermittent fevers, such as used to prevail
in marshy or ill-drained lands much more commonly than now in
Great Britain; though country folk still use the infusion or decoction
for the same purpose in some districts; also for jaundice.
Likewise, because of the tannin contained in the outer bark of the
roots, their decoction is useful against diarrhoea; and their infusion
as a gargle for relaxed sore throats. But, except in mild cases, other
more positively astringent herbs are to be preferred. The roots afford
a useful red dye.