This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
This is one of the Arctic plants which have been detected in early deposits, e.g. Interglacial, Late Glacial, Neolithic, and Roman deposits. The range to-day is Arctic Europe, West Siberia, the Azores, or the Northern and Arctic Temperate Zones. Commonly dispersed throughout Great Britain, it is found as far north as the Shetlands. In the Highlands it is found at the height of 3300 ft. It is a native of Ireland and the Channel Islands.
Tormentil is essentially an ericetal plant, being found on most of our commons and heaths, where Furze or Broom occurs along with Tussock Grass, and Grassy Stitchwort, Lesser Spearwort, etc. It is xerophilous, loving best dry pastures, where Milkwort, Heath Bed-straw, Heath, Whortleberry, Eyebright, Woodrushes, Heath Hair Grass, and Matweed are usually found.
All herbalists know the red woody rootstock of Tormentil, for it is a favourite plant with them, and those who study botany will not neglect to collect it in preserving their specimen of it. The stems, which are numerous, are suberect, the lower leaves being quinate, divided into five, and stalked, the others stalkless, the leaflets being wedge-shaped, lance-shaped, coarsely toothed at the end, clasping the stem, and downy both sides.
The flowers are smaller than in most of the Cinquefoils, and there are 4, not 5, petals, drooping at first, then erect (hence the second Latin name, applying equally to the stem). There are 8 sepals, which are downy. The seeds are naked, yellow, and net-veined. The receptacle is not fleshy as in Fragaria.
The plant is usually 6 in. high. It flowers during June and the intervening months up to September. Tormentil is like other deciduous, herbaceous plants, reproduced by seeds.
The floral arrangements are similar to those in P. verna, but the secretion of the honey is more evident, and as a thin layer. The anthers spread out in a flat disk and open along their margins as in Fragaria, and they are coated with pollen only along their edges. The plant is visited by Apidae, Andrena, Bombylidae, Systoechus, Syrphidae, Chrysotoxium, Melithreptes, Cheilosia. The anthers and stigma ripen at the same time.
The fruit consists of achenes, which are dispersed when dry by falling away from the parent plant, and so the plant is dispersed by its own agency.
A fungus, Phragmidium tormentilloe, infests it, and it is galled by Xestophanes brevitarsis. A beetle, Meligethes erythropus, a Hymenop-terous insect, Andrena analis, a moth, Teras caspersana, feed upon it.
The second Latin name refers to its relatively erect habit. It is called Biscuit, Blood-root, Earthbark, Ewe Daisy, Five-fingers, Flesh-and-blood, Sheep's Knapperty, Sept-foil. Set-foil, Seven-leaves, Shepherd's Knot, Shepherd's Root, Thormantle, Tormentil, Turnmentille. Sept-foil refers to the seven leaves, though there are often only five. It is called Earthbark in the Shetlands. As it is very astringent it is used for oak-bark in tanning. The name Blood-root arose from its red root, and by Doctrine of Signatures it was used for dysentery. Flesh-and-blood has the same origin.
The plant was an old cure for ague. Because it was used to cure toothache it was called Tormentil. It was also early used for stone. The rootstock is woody, and yields a red colour to leather and wood in Lapland. For tanning leather the roots have been boiled in water, and the leather steeped in the liquid when cold. A dye of a red colour has been obtained from it. It is used for a gargle, and lotion for ulcerated mouths and for sores.
Essential Specific Characters: 99. Potentilla erecta, Hampe. - Rootstock woody, stem ascending. radical leaves quinate, petiolate, leaflets acute, 3-5, flowers small, cy-mose, yellow, petals 4, carpels wrinkled.