Images: ©Jouko Lehmuskallio
Tormentil
Potentilla erecta
- Family: Rose Family – Rosaceae
- Height: 10–30 (4–12 in.) cm. The ascending stems are up to 50 cm (20 in.) long.
- Flower: Regular (actinomorphic). Petals four, yellow, broad, 4–6 mm (0.15–0.25 in.) long, and slightly notched. Calyx-lobes four, ca. 3 mm long, elliptic, sharp-pointed, hairy. Epicalyx-lobes narrow, almost as long as calyx-lobes. Carpels free, usu. four to eight. Stamens usu. sixteen.
- Leaves: Alternate. Trifoliolate, rarely palmate with five leaflets. Lowermost leaves long-stalked. Upper leaves stalkless. Leaflets obovate, toothed near tip, more or less hairless above, densely short-hairy beneath. Stipules large, often palmately lobed.
- Fruit: A roundish, greyish-brown, and ridged achene with one edge straight and sharp.
- Habitat: Meadows, roadsides, dry meadows, damp forests, spruce swamps. In the north mostly eutrophic fens and margins of other rich mires.
- Flowering time: June–August.
The perennial tormentil is, together with the marsh cinquefoil (P. palustris), the most common species of Potentilla in the Nordic countries. It can be distinguished from its relatives by the four-parted corolla and calyx. Originally a plant of swamps and fens this species has gained plenty of new habitats in association with agriculture.
The rootstock of the tormentil, weighing up to half a kilogram, formerly had several domestic uses. Substances obtained from it where used e.g. against dysentery. The stock is also good for tanning leather, dyeing (yielding a red dye), and seasoning.
