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 an Arctic plant found in Pre-, Inter-, and Late Glacial, Neolithic, and Roman deposits. It is a plant of the Cold Temperate and Arctic regions, found in Arctic Europe, North and W. Asia, as far as the Himalayas, and in North America. So widely distributed a plant occurs in every part of Great Britain, and in Scotland grows at 3400 ft. in the Highlands. It is found in Ireland.
The Marsh Marigold is hygrophilous, i.e. fond of moisture, always confined to marshy tracts, where there are some lime salts in the soil. It is associated in spring with the early-flowering sedges, and sallows, and osiers, and with it grow the marsh-loving Horse-tail, and the pale lilac-tinted Cuckoo Flower or Lady's Smock. In such marshy tracts it forms big clumps which cover the water-meadows as with intertwining chains of gold. It prefers the damp hollows where it is half-rooted in spongy, watery ground. It is found also by stream-sides and in swampy woods. The Marsh Marigold has a prostrate or somewhat erect habit. The plant is dark-green, rank, hairless, forming conspicuous clusters with attractive blooms. The rootstock is horizontal, short, the stem not rooting at the nodes. The stem may be erect or ascending. The radical leaves are long-stalked, rounded, heart-shaped, with two deep lobes at the base, and a narrow sinus, scalloped, toothed, glossy. The stipules are membranous, entire in bud, and enclose the leaf. The flowers are few, terminal, regular, large. Sepals of a bright yellow colour take the place of the petals. They are overlapping and close, unequal, round to egg-shaped. The follicles are spreading, with a very short beak, and many-seeded.
Photo. Matson - Great Spearwort (Ranunculus Lingua, L.)
Photo. J. H. Crabtree - Marsh Marigold (Caltha palustris, L.)
Marsh Marigold is 1-1 1/2 ft. high. Flowers may be found from March to May, and this is a perennial plant.
The flower is rendered conspicuous by the petaloid yellow sepals. There is an abundance of honey, which is secreted in two shallow depressions below the ovary, and is protected, as there are no petals, by a fold which helps to retain it. The plant is homogamous, that is to say the stigma and the pistil ripen at the same time, and in the ordinary course, as they are more or less on a level, self-pollination would result. But the flowers are much visited, and hence they are frequently cross-pollinated. Furthermore, the anthers open away from the centre or pistil, i.e. outwards, the outer series first. There are in some countries flowers which have no pistil, a further reduction of the floral axis, along with the ordinary type.
The flowers are 40 mm. in diameter, and hence attractive. The visitors are Diptera (Stratiomyidae), Odontomyia, (Syrphidae), Cheilosia, Ascia, Rhingia, Eristalis, (Muscidae), Scatophaga, Anthomyia; Cole-optera (Nitidulidae), Meligethes; Hymenoptera (Apidae), Andrena, Osmia rufa, Bombus terrestris, Apis mellifica, etc.
The seeds are dispersed by the wind. The aggregate fruits consist of many follicles, with many seeds which are blown out by the wind when the follicle is ripe and dry.
Puccinia calthoe is a fungus which infests it, as does Pseudopeziza calthoe.
The beetles Donacia dentipes, D. lemnoe, Prasocuris hannoverana feed on it, and the Homopterous insect Dorthesia urticoe.
Caltha, given by Pliny, is the Latin name of some plant, probably the Pot Marigold, and palustris refers to its marshy habitat. The English name is from Mary (i.e. Virgin Mary), and gold, in allusion to its colour.
This plant is called Bassinet, Blob, Boots, Bullflower, Butter-blob, Big Watercup, Great Butter-flower, Carlock-cups, Chirms, Claut, Crow Cranes, Crazy, Dandelion, Drunkard, Fire o' Gold, Water Goggles, Golden Cup, Gollin, Halcups, John Georges, Johnny Cranes, King-cob, Marsh Mallow, Mare-blob, Mayflower, Meadow Bouts, Moll-blob, Publicans and Sinners, Soldier's Buttons. In Oxfordshire Marsh Marigolds and Buttercups are called Publicans and Sinners.
"The wild marsh marigold shines like fire." - Tennyson: alluding to the name Will (Wild) fire. It is called Open Gowan from its open flowers, as opposed to the closed flowers of the Lockin Gowan.
It is said in Iceland that if the Marsh Marigold is taken with certain ceremonies and carried about it will prevent the wearer from having an angry word spoken to him. It is very acrid and poisonous, and those who have eaten it have been affected by it. The buds are salted and pickled in the same way as capers. From the "petals" a yellow dye is extracted, after boiling with alum. It is not eaten by cattle unless there is a lack of other herbage. Children use it for making garlands on May Day. The "petals" are often eaten by a beetle (Chrysomela).
Essential Specific Characters: ii. Caltha palustris, L. - Stems numerous, erect, leaves reniform, large, shiny, sepals yellow, large, petals wanting, follicles with short beak.