Tormentil is described by Weiss as the main vegetable astringent. Astringency in the widest sense must be the theme for this herb. Tannins have been identified as the astringent compounds in medicinal plants. They exert their effects through local action in the digestive tract in, for example, diarrhoea. The extent to which such large compounds are absorbed into the systemic circulation is a current topic of research but compounds which derive from tannins must be absorbed and be responsible for these actions. Tormentil can be of exceptional value as an astringent in heavy periods, and, although this action is not explained, it is one of those actions exerted by medicinal plants, of which perhaps the action of comfrey Symphytum ojficinale in bruising is the archetype, where once seen, always believed. ‘Probatus est’ as the old writers called it.
Dioscorides (IV 42) describes pentadactylon (‘five fingers’ in Greek) with five leaves on a petiole, saw edged all around, with a pale white flower, found growing in damp places and around water conduits. The Potentilla named pentadactylon by Dioscorides could be Potentilla alba, which has five white petals and five-fingered leaves that are only saw edged at the end. Beck gives Potentilla reptans, which is yellow like Potentilla erecta, for tormentil, which cannot be correct as Dioscorides describes a white flower. Dioscorides refers to a reddish root and, as red is the color associated with tannins, this plant can be identified as a Potentilla but is not tormentil. Fresh roots of tormentil are brown with a black surface but aqueous extracts and tinctures of Potentilla are a rich, deep red-brown. Dioscorides refers to uses in intermittent fevers and jaundice for the leaves; this usage is taken up by later authors mainly when discussing cinquefoil and must be associated with other Potentilla species.
Dioscorides says that pentadactylon is cut for religious ceremonies and purifications, which suggests a larger plant as he also refers to the sprays, which are a span long, like dry sticks and bear fruit. Pliny appears to be referring to the same herb when he describes cinquefoil with a red root which turns black on drying, ‘commendable for the strawberries it bares’ and used to bless a house against evil spirits. The possible identity is discussed at length by Parkinson, who reviews the names given for pentadactylon by the authors. As Turner argues, it must be a cinquefoil, also named quinquefolium, five-fingered grass or the five-fingered herb. Turner includes tormentil in his third volume, which covers herbs not found in Dioscorides. Galen refers to pentaphyllum, a five-leaved plant, cinquefoil, as very drying in the third degree with a minimum heat and little sharpness, so very useful. Dioscorides, Pliny, Galen and Theophrastus, according to Parkinson, all refer to a plant with a five-fingered leaf, which is therefore not tormentil but will be another Potentilla species, probably one of the cinquefoils.
Other Potentilla species are referred to by the Renaissance authors and it seems likely that various Potentilla species were used. Fuchs (1980) gives quinquefolium luteum maius which is five fingered and could be Potentilla reptans and quinquefolium luteum minor. Fuchs also gives argemone altera uel potentilla, which appears to be silver-weed and states that it has the character of quinquefolium and therefore can be used when an astringent is required. Fuchs gives an illustration of ‘heptaphyllum’ that appears to be tormentil. Interestingly, Parkinson comments that tormentil is not found in Dioscorides yet has acquired the Greek name of heptaphyllum. Today, Potentilla heptaphylla is a mat-forming plant with tiny toothed leaves which is found in eastern Europe but not in Britain. Dodoens refers to tormentil as a plant with seven leaves on a stem, growing in dark and shadowy woods and green ways, which flowers all summer. He describes leaves with snipped, toothed edges and Dalechamps gives a very similar description. Parkinson discusses the plants suggested by other authors as being the pentaphyllum of Dioscorides and Theophrastus and disagrees with Tragus (Bock), who argues that tormentil must be equivalent as it is the ‘best and most noble pentaphyllum’, as he points out that the plant of Dioscorides had distinctive five-parted leaves and whitish flowers. Parkinson makes a long diversion into the question of leaves and argues that the leaves of Potentilla species are made up of leaflets as they wither and fall in one piece. As discussed below, Parkinson inherited the notes of de l’Obel and one wonders whether these are the words of de l’Obel, who studied leaves in depth having developed a classification system for plants based on leaf form.
Parkinson gives tormentil first but then states that the cinquefoils will do as well. He divides the cinquefoils into three categories: those with white flowers, those with yellow flowers which creep on the ground with a lax habit, and erect plants with yellow flowers. Parkinson recommends use of common cinquefoil, pentaphyllum vulgarissimum, which he describes as having yellow flowers, spreading by runners like strawberries, with toothed, five-fingered leaves, and blackish brown roots ‘seldom as thick as the little finger’ but spreading quickly by creeping along the ground. This could be Potentilla reptans. Parkinson states that Bauhin names it quinquefolium majus repens and Hill (1756) repeats the recommendation and lists this cinquefoil as Pentaphyllum vulgare stating that Gaspard Bauhin names it quinquefolium majus repens, and Jean Bauhin pentaphyllum vulgare repens. These names are confusing but are reproduced to show how much the Linnean binomial system was rooted in the labours of preceding authors.
The conclusion thus far is that the authors refer to various Potentilla species and the roots are used interchangeably. Cultivation of these species would allow for more definitive recommendations. For this book we have selected herbs that are commonly used by herbalists, yet we have discovered enormous problems in both the identification of similar members of the same genus, and in the interpretation of recommendations where it is unclear which herb was originally used. One of the main aims of the Renaissance writers such as Turner, Fuchs, Dodoens, Mattioli and Parkinson was to determine the correct species. Yet as a profession we still have some way to go today in this matter because of the continuing wild collection of many medicinal plants (ISSC-MAP 2009). Parkinson expresses his frustration, while discussing hermodactylus (see below), at the ‘shame of the physicians’ who leave these matters to apothecaries and merchants, but should ‘give orders that the unknown should be made more manifest’. Yet he feels that his admonitions will be pointless, ‘but what do I in so saying run my Barke (ship) upon the Rockes and put her in danger of splitting’.