This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
Unlike the Tormentil this plant has not been discovered in any early deposits. Its distribution in the Northern Temperate Zone is confined to Europe from Gothland southward, N. and W. Asia, Himalayas, Canaries, Azores. In Great Britain it is a common plant, but it is not found in Cardigan, S. Perth, Mid Perth, N. Aberdeen, Elgin, Easterness, Main Argyle, Dumbarton, Clyde Islands, Ebudes, and the whole of the N. Highlands, and Northern Isles, ranging thus from Banff southward. It is a native in Ireland and the Channel Islands.
The common Yellow Cinquefoil is a familiar plant in the meadows and fields when in bloom, covering some few feet with its golden flowers and creeping stem. It is addicted to little knolls and banks, and being fond of dry soil prefers high ground, spreading rapidly on the hillside or open meadow.
The common English name Cinquefoil describes the fivefold arrangement of leaflets in this plant, and the second Latin name describes its habit, creeping, the stem lying quite flat. It is usually a larger plant than Tormentil, and the stem is slender, thread-like, rooting at intervals. The leaves are larger, and are stalked, having finger-like, toothed leaflets, blunt at the tip, with some small leaves in the axils in pairs, and slightly hairy.
The flowering stalks bear solitary flowers and are long, in the axils, and half-erect, with large flowers, the sepals being alternately smaller, the petals heart-shaped. The achenes or fruits are rough, the seeds numerous.
Cinquefoil being a plant which lies on the ground is never more than 6 in. in height. It flowers freely in June and July. It is perennial and propagated by runners.
Photo. L. K. J. Horn - Common Yellow Cinquefoil (Potentiha Reptans, L.)
The flower is like that of P. verna, in which there is a ring-like ridge on the inner wall of the tube borne on the top of the flower-stalk, which surrounds the base of the stamens, and is marked by its dark reddish-yellow colour. The honey is not secreted in drops, but in a very evident, smooth adherent layer. The anthers become covered on both sides with pollen, and ripen at the same time as the stigmas.
Insects alight in the centre, or on the petals, and in the latter case they dust themselves with pollen, but do not touch the stigmas, as the honey-ring lies farther out. If they alight in the middle of the next flower they cross-pollinate it. But the flower is often self-pollinated. The flowers close up in part in dull weather, and completely at night, and it is then that the anthers touch the stigmas.
The visitors are Prosopis armillata, P. hyalinata, Ha/ictus macu-latus, II. leucozonus, H. sexstrigatus, Andrena albicrus, A. nana, Sphecodes gibbus, Nomada xanthosticta, N. succincta, Ammophila sabu/osa, Syrphus arcuatus.
The achenes or fruits are granulated or covered with little points, and are dispersed, when dry, around the parent plant.
A dry sand soil is the principal requirement of Cinquefoil, which is strictly a sand plant, growing luxuriantly on sand, derived from sedimentary rocks or even directly from older granitic debris.
Xestophanes potentillae forms galls upon the stems and rhizomes, and a moth, the Knotgrass (Acronycta rumicis), feeds on the Cinquefoil.
The second Latin name refers to its creeping habit. It is called Cinquefoil, Fiflef, Five-finger-blossom, Five-finger-grass, Five-fingers, Five-leaf, Five-leaved-grass, Golden-blossom, Herb Five-leaf, Sink-field, Synkefoyle, Tormentil. Sinkfield is merely a corruption for Cinquefoil, which alludes to the five leaflets.
In the fourteenth century it was much used, and imagined to be a cure, for stomach complaints. Like Tormentil it is astringent and used in dysentery, being also used for tanning. Tea used for fevers was made with it.
Essential Specific Characters: 100. Potentilla reptans, L. - Stem slender, rooting, creeping, leaflets obovate, leaves stalked, flowers large, yellow, petals five, obcordate, carpels rough.