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.
This is an ancient plant, having been met with at Edinburgh in beds of Neolithic age. It is found in the North Temperate and Arctic Zones in Arctic Europe, N. Africa, N. and W. Asia, as far east as the Himalayas. In America it is an introduction. It is found in every part of Great Britain also, as far north as the Shetland Islands, and it ascends to 2700 ft. in the Highlands. It is native in Ireland and the Channel Islands.
Coltsfoot is a pelophilous plant which grows on clay soils in damp situations, on banks in clay pits, on railway banks, by the sides of streams, and other places where there is a steady flow of water in the spring.
The plant is prostrate in habit. The plant is soboliferous, with many long underground shoots, ending in suckers. It has burrowing stolons, by which it spreads extensively. The only aerial stem is the 1-flowered scape. The leaves are broad, round to heart-shaped, angular, or lobed, downy or woolly-felted below, toothed. The stomata on the under surface are no doubt protected by the woolly felt. The upper surface is glossy or cobwebby, with the veins prominently hollow, and below they stand out under the felt. The leaves do not appear until after the scapes.
The scapes are downy, one or more, the flowerheads bright yellow, and erect in bloom and in fruit, drooping in bud and after flowering. The scapes are covered by numerous oblong, closely pressed, smooth scales or bracts. The involucral bracts are in one row, with few outer shorter ones. The ray florets are in many rows, narrow, ligulate, the disk florets being bell-shaped, with 5 teeth. The stigma is club-shaped, the arms united below, papillose, with 2 small cones. The anthers have no tails. In the ray florets the fruit is nearly cylindrical, that of the disk florets imperfect, with pappus in one row. The pappus is snowy-white, soft, forming a globular clock when fully expanded, and readily dispersed when ripe. The hairs are slender, rough.
Photo. B. Hanley - Coltsfoot (Tussilago Farfara, L.)
Coltsfoot is scarcely more than 6 in. in height in flower. The flowers bloom in March and April. The Coltsfoot is a herbaceous perennial plant, propagated by division.
The solitary yellow flowerheads or capitula are very conspicuous in the spring, being 20-25 mm. across when outspread, and have a distinct and strong smell, which with the honey they contain renders them especially attractive to early flying insects at a time when few flowers, save the Sallow, are in bloom. The plant is monoecious. In the ray the florets are female (hence the fully-developed achenes at a later stage only in the ray). The disk florets are male. Both disk and ray florets are golden-yellow, and there is little to distinguish them at first sight, but those in the ray are ligulate, those in the disk bell-shaped. In the ray florets, which are numerous, over 300, there is a pollen brush which is not of any use in female florets, and it may be that there were originally male florets also, but this provision is not usual in female florets in this order. The disk florets are much fewer, about 40 in number, and alone contain the honey. The flowerheads close at night, and when there is rain, as a protection for the honey and pollen. When the ray florets have been visited and pollinated they do not wither as is usual at once, but remain fresh till the anthers have opened some days after. Insect visitors are numerous. The disk florets retain a rudimentary pistil. In the ordinary course the flowers are cross-pollinated, the proterogynous flowerheads ensuring this.
Self-pollination without insects is impossible. The flowers are visited by the Honey Bee, Andrena, Halictus, Diptera (Bombylius major, Eristalis tenax), Coleoptera (Meligethes).
The plant is provided with white silky pappus to aid the fruit in dispersal by the wind.
Coltsfoot is a clay-loving plant, being confined to a clay soil.
The leaves on the upper side are covered with a large "cluster-cup" fungus, Coleosporium sonchi, which is a beautiful object under the lens. The stomata lie below covered with felted down, which is greyish-white.
A Hymenopterous insect, Mellinus sabulosus, Lepidoptera, Glaucous Shears (Hadena glauca), Halonota brunichiana, Scopula lutealis, Ptero-phorus trigonodactylus, are to be met with on this food plant.
Tussilago, Pliny, is from tussis, a cough, with reference to its use in curing coughs. Farfara, Pliny, is a Latin name for the plant.
The name Colt's-foot is given because of the shape of the leaf. It is called Ass's-foot, Bull-foot, Clatter-clogs, Clayt, Clayweed, Cleats, Clot, Colt-herb, Colt's-foot, Coughwort, Cout-fit, Cow-heave, Dishalaga, Dove-dock, Dummy Weed, Foalfoot, Foilefoot, Tushylucky Gowan, Hog-weed, Hoofs, Horse-hoof, Horse-hove, Son-before-the-Father, Sow Foot, Tushalan. The name Son-before-the-Father is the name given because the flowers appear before the leaves. Wine made from it is called Clayt wine, and beer made from it Cleats, and these with the name Clayweed refer to its clay habitat. Colt's-foot, Cow-heave (a cow hoof), Hoofs, Horse-hove, refer to the same resemblance between the leaf outline and an ungulate hoof.
On Easter Day in Bavaria the peasants made garlands of it and threw them into the fire. It has been considered a demulcent and pectoral, the leaves being mucilaginous. The plant has long been used for coughs. In Chaucer's day it was used in all stomachic complaints, for broken bones and the drye cohw (cough). The leaves are held to be expectorant. The leaves have been used since the days of Dioscorides to smoke through a reed to remove the mucus in the chest for catarrh, asthma, phthisis, but it is little used to-day. The cotton of the leaves wrapped in rag dipped in saltpetre has been employed as tinder. For coughs also a tea or syrup was made. The root dried and burnt has been used to keep away gnats.
When the florets have done blooming, and the achenes with pappus enclosed in the involucre are moist, the heads hang down, as at night, but in the day and when it is dry they become light, and the scape is again erect and the pappus expanded as in the Dandelion.
Essential Specific Characters:163. Tussilago Farfara, L. - Soboliferous, leaves large, cordate, angular, with dark teeth, cottony beneath, leaves appearing after the flowerheads, which are on scapes with scales, disk florets tubular, ray florets ligulate, drooping before and after flowering.