''Mercurialis perennis'', commonly known as dog's mercury, is a poisonous woodland plant found in much of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
as well as in Algeria, Iran, Turkey, and the Caucasus, but almost absent from
Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
,
Orkney
Orkney (; sco, Orkney; on, Orkneyjar; nrn, Orknøjar), also known as the Orkney Islands, is an archipelago in the Northern Isles of Scotland, situated off the north coast of the island of Great Britain. Orkney is 10 miles (16 km) north ...
and
Shetland
Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom.
The islands lie about to the no ...
.
Altervista Flora Italiana, Mercorella bastarda, ''Mercurialis perennis'' L.
includes photos, drawings, and a European distribution map A member of the spurge family (Euphorbiaceae
Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, e ...
), it is a herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition of t ...
, downy perennial with erect stems bearing simple, serrate leaves. The dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
s are green, bearing inconspicuous flowers from February to April. It characteristically forms dense, extensive carpets on the floor of woodlands and beneath hedgerows.
Growth and location
''Mercurialis perennis'' is a herbaceous plant. It usually grows in dense masses often in the ground flora of beech, oak, ash, elm and other types of woodlands in Europe.[Mukerji, S. K. (1936). Contributions to the autecology of Mercurialis perennis L. Journal of Ecology, 24(1), 38-81.] It also grows under the shade of hedgerows and scrub. It has a preference for moderately shady to densely shady habitats. It is able to colonize new deciduous woods on dry, calcareous soils at an annual rate of a meter or more.[ Under such conditions, the plants, especially the females, often display a darker green color. Its period of reproductive activity depends upon a number of factors such as illumination, soil reaction, soil moisture, etc. These factors also affect the duration of reproductive activity.]
Dog's mercury favors alkali
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a ...
ne (basic) soils and can be found in abundance in suitable habitats in limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
regions. It also occurs widely on neutral soils but is absent from acid
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
ic ones. Spreading by underground rhizomes
In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
, where its dense growth may shade out other woodland flowers such as oxlip
''Primula elatior'', the oxlip (or true oxlip), is a species of flowering plant in the family Primulaceae, native to nutrient-poor and calcium-rich damp woods and meadows throughout Europe, with northern borders in Denmark and southern parts of ...
, fly orchid
''Ophrys insectifera'', the fly orchid, is a species of orchid and the type species of the genus ''Ophrys''. It is remarkable as an example of the use of sexually deceptive pollination and floral mimicry, as well as a highly selective and highly ...
, and even young ash
Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
seedlings,[Mabey, Richard, '']Flora Britannica
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''.
E ...
'', Sinclair-Stevenson
Sinclair-Stevenson Ltd is a British publisher founded in 1989 by Christopher Sinclair-Stevenson.
Christopher Sinclair-Stevenson became an editor at Hamish Hamilton in 1961. Thirteen years later in 1974 he became managing director, establishing ...
, London, 1996, pp256–257. but in the open, it eventually gives way to other plants.
''Mercurialis perennis'' extends from sea level to the mountain range. The ultimate height attained in different mountainous regions, e.g. in Scotland, England, Germany, and Switzerland, naturally varies with the latitude and other geographical factors. Existing colonies in some parts of Britain (including some in woods on boulder clay
Boulder clay is an unsorted agglomeration of clastic sediment that is unstratified and structureless and contains gravel of various sizes, shapes, and compositions distributed at random in a fine-grained matrix. The fine-grained matrix consists ...
in East Anglia
East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...
), are expanding and showing increased vigor, perhaps as a result of deeper shade in woodlands where coppicing
Coppicing is a traditional method of woodland management Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, pro ...
has ceased.[
]
Names
The plant's common name derives from the plant's resemblance to the unrelated ''Chenopodium bonus-henricus
''Blitum bonus-henricus'' ( syn. ''Chenopodium bonus-henricus''), also called Good-King-Henry, poor-man's asparagus, perennial goosefoot, Lincolnshire spinach, Markery, English mercury, or mercury goosefoot, is a species of goosefoot which is na ...
'' (Good King Henry, also known as mercury, markry, markery, Lincolnshire spinach). Since ''Mercurialis perennis'' is highly poisonous, it was named "dog's" mercury (in the sense of "false" or "bad").[ It has also been known as boggard posy.
]
Categorization
There are separate male and female plants (the species is dioecious). the plants are born at the base of the leaves similar to nettle
{{redirect, Nettle
Nettle refers to plants with stinging hairs, particularly those of the genus ''Urtica''. It can also refer to plants which resemble ''Urtica'' species in appearance but do not have stinging hairs. Plants called "nettle" include ...
s. The flower spikes (about long) appear between February and May. The catkin
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). They contain many, usually unisexual flowers, arranged cl ...
-like male flowers have a yellow color (due to yellow stamens) and female flowers have 3 tepals (petals and sepals are combined or indistinguishable).
Taxonomy
The genus ''Mercurialis'' belongs to the family Euphorbiaceae
Euphorbiaceae, the spurge family, is a large family of flowering plants. In English, they are also commonly called euphorbias, which is also the name of a genus in the family. Most spurges, such as ''Euphorbia paralias'', are herbs, but some, e ...
and to the subfamily Crotonoideae
The Crotonoideae (crotonoids) are a subfamily within the family Euphorbiaceae.
See also
* Taxonomy of the Euphorbiaceae
Here is a full taxonomy of the family Euphorbiaceae, according to the most recent molecular research. This complex famil ...
. It is included in the tribe Acalyphae, which is characterized by clusters of flowers It is also characterized by the lack of any laticiferous tissue, in the place of which tanniniferous cells (or tissue) are sometimes found.
According to Pax (1914), there are three other genera related to ''Mercurialis''; ''Seidelia
''Seidelia'' is a plant genus of the family Euphorbiaceae first described as a genus in 1858. The genus is endemic to Southern Africa (South Africa and Namibia).Govaerts, R., Frodin, D.G. & Radcliffe-Smith, A. (2000). World Checklist and Bibliogr ...
'', ''Leidesia
''Leidesia'' is a monotypic plant genus in the family Euphorbiaceae first described as a genus in 1866. The sole species is ''Leidesia procumbens''. The species is widespread in Southern Africa as far north as Democratic Republic of the Congo.
T ...
'' and ''Dysopsis
''Dysopsis'' is a genus of plants in the family Euphorbiaceae, first described in 1858.
It is the sole genus in subtribe Dysopsidinae. The genus is native to Costa Rica, Panama, South America, and the Juan Fernández Islands.González Ramírez ...
''. The differences between these are based on the characteristics of the calyx and stamens.
The genus ''Mercurialis'' itself consists of nine species and the main taxonomic characteristics used in distinguishing them are the clusters of floration, the annual or perennial
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
habit, and the glabrous or hairy condition of the vegetative organs, but chiefly the ovary and the capsule, the woody or herbaceous nature of the plant, and lastly the character of the lamina.
Plant community
Dog's mercury is one of the characteristic plants of several woodland types, in particular:
* W8 ''Fraxinus excelsior - Acer campestre - Mercurialis perennis'' woodland
* W9 ''Fraxinus excelsior - Sorbus aucuparia - Mercurialis perennis'' woodland
* W12 ''Fagus sylvatica - Mercurialis perennis'' woodland
Variations in morphology
M. perennis has variation in its morphological characters. This is noticeable in the outline, shape, and hairiness of its leaves, in the size of the lower leaves, in the number of stamens, and in the size of the seeds and fruits.
M. perennis possesses three distinct varieties are:
# M. perennis L. var. genuina Miiller-Aarg
# M. perennis L. var. Salisburyana Mukerji (Mukerji, 1927).
# M. perennis L. var. leiocarpa Mukerji (syn. M. leiocarpa Sieb. et Zucc.)
Note:- M. perennis L. var. Salisburyana Mukerji (Mukerji, 1927) was discovered in March 1926 at Staplehurst (Kent). It differs from M. perennis L. var. genuina Miiller-Aarg in the following respects:
* serrated leaf margin
* shorter petiole
* darker green color
* more hispid character
* shorter and upwardly directed stigmas
Habitat variation
Besides those three variations of ''M. perennis'' there are six habitat forms in nature:
* f. silvatica (Hoppe s. str.). Leaves elongated, elliptic-lanceolate, pointed. Mid-nerve and veins of the leaves usually are thicker.
* f. ovatifolia (Hausskn.). Leaves ovate to ovate-lanceolate, the upper part of the stem above the middle region generally hangs down. This form grows on sunny slopes in bushes and thickets or on entirely exposed dry situations.
* f. angustifolia (Murr.). Grows, like the preceding, in sunny situations, but the leaves are comparatively narrow and lanceolate, more hairy and thicker.
* f. robusta (Gross). Leaves unusually large, 10–15 cm long, and over 5 cm. broad. Seeds 4–5 mm long. Plants very much taller and more robust, sometimes attaining a height of about 60–65 cm. Generally found under old oak or beech in fairly damp and shady localities.
* f. saxicola (Beck.). Leaves elongate-elliptic, 4-5 times as long as broad, gradually tapering towards the apex. Both the upper and lower faces of the leaves hairier. Generally on exposed chalky hills.
* f. variegata (Mukerji). Its leaves possess beautiful mottled patches of yellow and white, and by continued cultivation, this may be further improved.
Chemical characteristics
All parts of the dog's mercury are highly poisonous. Methylamine
Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.
Methylamine is sold as a solution in methanol, ...
(mercurialine) and trimethylamine
Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a colorless, hygroscopic, and flammable tertiary amine. It is a gas at room temperature but is usually sold as a 40% solution in water. (It is also sold in pressurized ...
are thought to be present, together with a volatile basic oil, mercurialine, and saponin
Saponins (Latin "sapon", soap + "-in", one of), also selectively referred to as triterpene glycosides, are bitter-tasting usually toxic plant-derived organic chemicals that have a foamy quality when agitated in water. They are widely distributed ...
s.[Cooper, Marion R, & Johnson, Anthony W, ''Poisonous Plants & Fungi – An illustrated guide'', ]HMSO
The Office of Public Sector Information (OPSI) is the body responsible for the operation of His Majesty's Stationery Office (HMSO) and of other public information services of the United Kingdom. The OPSI is part of the National Archives of the Un ...
, London, 1991, pp48–49,
The scent of the plant is often described as 'foetid' due to the presence of trimethylamine which often gives off a rotting fish smell. Mercurialine is thought to be one of the active principle parts that are responsible for the toxicity of the herb.[ It is known to induce hemorrhagic inflammation of the gastrointestinal tract and kidneys. There is apparently some narcotic action, which induces drowsiness, and mild muscular spasms.][
One hypothesized mechanism of toxicity was discovered in 1900s. A researcher induced toxicity with dog's mercury, frozen at different stages of growth and fed it to sheep. Based on this experiment, these effects may be due to different toxic factors that are developed at different growth stages.][ Another hypothesis is that one toxin might be culpable for the symptoms and illness.][
Solanine.svg, saponin
Methylamine.svg, methylamine
Trimethylamin.svg, trimethylamine
]
Symptoms of poisoning
Symptoms of poisoning appear within a few hours; they can include vomiting, pain, gastric and kidney inflammation, and sometimes inflammation of the cheeks and jaw (" malar erythema") and drowsiness. Larger doses cause lethargy
Lethargy is a state of tiredness, sleepiness, weariness, fatigue, sluggishness or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overwo ...
, jaundice
Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme meta ...
, painful urination, apparently by making the urine acid, and coma before death.
Reported cases of poisonings
The first-known account of this phenomenon probably dates from 1693, when a family of five became seriously ill as a result of eating the plant (after boiling and frying it); one of the children died some days later as a result.[
Apart from ''Chenopodium bonus-henricus'' and some other edible members of the ]Chenopodiaceae
Amaranthaceae is a family of flowering plants commonly known as the amaranth family, in reference to its type genus ''Amaranthus''. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, making it ...
(also known as mercuries), the most similar-looking species is probably ''Mercurialis annua
''Mercurialis annua'' is a species of flowering plant in the spurge family Euphorbiaceae known by the common name annual mercury or (rarely) French mercury. It is native to Europe, North Africa, and the Middle East but it is known on many other c ...
'', annual mercury, which is also thought to be poisonous.[ Dog's mercury has been eaten in mistake for ]brooklime
''Veronica beccabunga'', the European speedwell or brooklime, is a succulent herbaceous perennial plant belonging to the flowering plant family Plantaginaceae. It grows on the margins of brooks and ditches in Europe, North Africa, and north and ...
.[
In 1983, a couple was reported of having eaten a large quantity of leaves after washing and boiling the plant after mistaking it for ]brooklime
''Veronica beccabunga'', the European speedwell or brooklime, is a succulent herbaceous perennial plant belonging to the flowering plant family Plantaginaceae. It grows on the margins of brooks and ditches in Europe, North Africa, and north and ...
.[ Both patients were hospitalized complaining of nausea, vomiting, and severe bilateral colicky loin pain and present signs of malar erythema but no signs of cardiovascular/respiratory disorders. They presented signs similar to an allergic reaction. They suffered severe gastrointestinal complications which led to dehydration. Once the toxin was identified, they were given sodium bicarbonate four times a day to neutralize the acidity of the urine. They recovered after two days of rest and continuous observation and monitoring.][
An outbreak of fatal mercurialis poisoning in the Welsh mountain ewes was reported which included ]hemolytic anemia
Hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular hemolysis) or elsewhere in the human body (extravascular). This most commonly ...
without marrow suppression and acute oedematous gastroenteritis with hepatic centrilobular necrosis.[Rugman, F., Meecham, J., & Edmondson, J. (1983). Mercurialis perennis (dog’s mercury) poisoning: a case of mistaken identity. British Medical Journal (Clinical Research Ed.), 287(6409), 1924.]
Uses
The dog's mercury is poisonous by itself but with a thorough drying/heating, one is able to destroy its poisonous quality. The juice of the plant is emetic, ophthalmic and purgative. It can be used externally to treat menstrual pain, ear, and eye problems, warts, and sores. A lotion can be made from the plant for antiseptic external dressing due to its ability to soften and moisturize the skin.
A fine blue dye can be obtained from the leaves although it is able to be turned red by acids and destroyed by alkalis. It is often permanent and colouration is similar to indigo
Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', m ...
. A yellow dye can be obtained from the leaves. The seeds are also a good source of drying oil
A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air, at room temperature. The oil hardens through a chemical reaction in which the components crosslink (and hence, polymerize) by the action of oxygen (not ...
.
References
External links
*
*
{{Taxonbar, from=Q158132
Acalypheae
Medicinal plants
Plants described in 1753
Flora of Europe
Flora of Algeria
Taxa named by Carl Linnaeus
Dioecious plants