''Alliaria petiolata'', or garlic mustard, is a
biennial
Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years.
In particular, it can refer to:
* Biennial plant, a plant which blooms in its second year and th ...
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
in the mustard family (
Brassicaceae
Brassicaceae () or (the older) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The le ...
). It is native to Europe, western and central Asia, north-western Africa,
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
,
Iberia
The Iberian Peninsula (),
**
* Aragonese and Occitan: ''Peninsula Iberica''
**
**
* french: Péninsule Ibérique
* mwl, Península Eibérica
* eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...
and the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
, north to northern
Scandinavia
Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...
, and east to northern
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
and
Xinjiang
Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwest ...
in western China.
In the first year of growth, plants form clumps of round, slightly wrinkled leaves, that when crushed smell like garlic. The plants flower in spring of the next year, producing cross shaped white flowers in dense clusters. As the flowering stems bloom they elongate into a spike-like shape. When flowering is complete, plants produce upright fruits that release seeds in mid-summer. Plants are often found growing along the margins of
hedge
A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoin ...
s, giving rise to the old British folk name of jack-by-the-hedge. Other common names include: garlic mustard,
garlic root, hedge garlic, sauce-alone, jack-in-the-bush, penny hedge and poor man's mustard. The genus name ''Alliaria'', "resembling ''
Allium
''Allium'' is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The generic name ''Allium'' is the Latin word for garlic,Gledhill, Davi ...
''", refers to the
garlic
Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus ''Allium''. Its close relatives include the onion, shallot, leek, chive, Allium fistulosum, Welsh onion and Allium chinense, Chinese onion. It is native to South A ...
-like odour of the crushed foliage.
All parts of the plant, including the roots, give off a strong odour like garlic.
Description
It is an
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 ...
biennial plant
A biennial plant is a flowering plant that, generally in a temperate climate, takes two years to complete its biological life cycle.
Life cycle
In its first year, the biennal plant undergoes primary growth, during which its vegetative structures ...
growing from a deeply growing, thin, whitish taproot scented like
horseradish
Horseradish (''Armoracia rusticana'', syn. ''Cochlearia armoracia'') is a perennial plant of the family Brassicaceae (which also includes mustard, wasabi, broccoli, cabbage, and radish). It is a root vegetable, cultivated and used worldwide ...
. In their first years, plants are
rosettes of green leaves close to the ground; these rosettes remain green through the winter and develop into mature flowering plants the following spring. Second-year plants often grow from tall, rarely to tall. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are stalked, triangular through heart shaped, long (of which about half being the
petiole) and broad, with coarsely toothed margins. The
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s are produced in spring and summer in small clusters. Each small flower has four white petals long and broad, arranged in a cross shape. The
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
is an erect, slender, four-sided capsule long, called a
silique
A silique or siliqua (plural ''siliques'' or ''siliquae'') is a type of fruit (seed capsule) having two fused carpels with the length being more than three times the width. When the length is less than three times the width of the dried fruit i ...
, green maturing to pale grey brown, containing two rows of small shiny black
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s which are released when a silique splits open. A single plant can produce hundreds of seeds, which often scatter several meters from the parent plant.
Depending upon conditions, garlic mustard flowers either
self-fertilize or are
cross-pollinated
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
by a variety of insects.
![Alliaria petiolataseeds](https://upload.wikimedia.org/wikipedia/commons/8/87/Alliaria_petiolataseeds.jpg)
Sixty-nine insect herbivores and seven fungi are associated with garlic mustard in Europe. The most important groups of natural enemies associated with garlic mustard were
weevil
Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...
s (particularly the genus ''
Ceutorhynchus
''Ceutorhynchus'' is a genus of true weevils in the tribe Ceutorhynchini. There are at least 400 described species in ''Ceutorhynchus''.
''Ceutorhynchus succinus'' Legalov, 2013 is a species from the Eocene of Europe found in Baltic amber.Ne ...
''),
leaf beetles
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle ...
,
butterflies
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the Order (biology), order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The ...
, and
moths
Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...
, including the
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e of some moth species such as the
garden carpet
The garden carpet (''Xanthorhoe fluctuata'') is a moth of the family Geometridae. It is an abundant and familiar species across its huge range which covers the whole Palearctic region from Ireland to Japan and including the Near East and North ...
moth.
The small white flowers have a rather unpleasant aroma which attracts
midge
A midge is any small fly, including species in several families of non-mosquito Nematoceran Diptera. Midges are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some mid ...
s and
hoverflies
Hover flies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while ...
, although the flowers usually pollinate themselves. In June the pale green caterpillar of the
orange tip butterfly (''Anthocharis cardamines'') can be found feeding on the long green seed-pods from which it can hardly be distinguished.
Cultivation and uses
Garlic mustard is one of the oldest spices used in Europe.
Phytolith
Phytoliths (from Greek, "plant stone") are rigid, microscopic structures made of silica, found in some plant tissues and persisting after the decay of the plant. These plants take up silica from the soil, whereupon it is deposited within different ...
s in pottery of the
Ertebølle and
Funnelneck-Beaker culture in north-eastern Germany and Denmark, dating to 4100–3750 BCE prove its use.
In the 17th century
Britain
Britain most often refers to:
* The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands
* Great Britain, the largest island in the United King ...
, it was recommended as a flavouring for salt fish. It can also be made into a sauce for eating with roast lamb or salad.
['']Reader's Digest
''Reader's Digest'' is an American general-interest family magazine, published ten times a year. Formerly based in Chappaqua, New York, it is now headquartered in midtown Manhattan. The magazine was founded in 1922 by DeWitt Wallace and his wi ...
Nature Lover's Library, Field Guide to the Wildflowers of Britain'', Editor Michael W. Davison, Art Editor Neal V. Martin, The Reader's Digest Association Limited, 11 Westferry Circus, Canary Wharf
Canary Wharf is an area of London, England, located near the Isle of Dogs in the London Borough of Tower Hamlets. Canary Wharf is defined by the Greater London Authority as being part of London's central business district, alongside Central Lo ...
, London E144HE, Reprint 2001, Early European settlers brought the herb to the
New World
The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...
to use as a garlic type flavouring. Its traditional medicinal purposes include use as a
diuretic
A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics in ...
.
The herb was also planted as a form of erosion control.
Today, the chopped leaves are used for flavouring in
salad
A salad is a dish consisting of mixed, mostly natural ingredients with at least one raw ingredient. They are typically served at room temperature or chilled, though some can be served warm. Condiments and salad dressings, which exist in a va ...
s and
sauce
In cooking, a sauce is a liquid, cream, or semi-solid food, served on or used in preparing other foods. Most sauces are not normally consumed by themselves; they add flavor, moisture, and visual appeal to a dish. ''Sauce'' is a French word t ...
s such as
pesto
Pesto () is a sauce that traditionally consists of crushed garlic, European pine nuts, coarse salt, basil leaves, and hard cheese such as Parmigiano-Reggiano (also known as Parmesan cheese) or Pecorino Sardo (cheese made from sheep's milk), a ...
, and sometimes the flowers and fruit are included as well. The leaves, best when young, taste of both garlic and mustard. The seeds are sometimes used in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
to season food.
Garlic mustard was once used medicinally as a
disinfectant
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than st ...
or
diuretic
A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics in ...
, and was sometimes used to treat wounds.
Toxicity
Young first-year garlic mustard plants contain up to 100ppm cyanide, a level which is toxic to many vertebrates. Once the plant is chopped up the cyanide gas is eliminated.
North America
Garlic mustard was introduced to North America by European settlers in the 1800s for culinary and medicinal purposes.
The species was recorded as being in
Long Island
Long Island is a densely populated island in the southeastern region of the U.S. state of New York (state), New York, part of the New York metropolitan area. With over 8 million people, Long Island is the most populous island in the United Sta ...
in 1868. It has since spread all over North America, apart from the far south of the US and some prairie states and Canadian provinces.
It is toxic or unpalatable to many native herbivores, as well as to some native
Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
.
The plant is classified as an
invasive species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
in North America. Since being brought to the United States by settlers, it has
naturalized
Naturalization (or naturalisation) is the legal act or process by which a non-citizen of a country may acquire citizenship or nationality of that country. It may be done automatically by a statute, i.e., without any effort on the part of the in ...
and expanded its range to include most of the
Northeast
The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...
and
Midwest
The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four Census Bureau Region, census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of ...
, as well as south-eastern Canada. It is one of the few invasive herbaceous species able to dominate the
understory
In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abov ...
of North American forests and has thus reduced the
biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...
of many areas.
Of the many natural enemies it has in its native range, several have been tested for use as
biological control agents. Five weevil species from the genus ''
Ceutorhynchus
''Ceutorhynchus'' is a genus of true weevils in the tribe Ceutorhynchini. There are at least 400 described species in ''Ceutorhynchus''.
''Ceutorhynchus succinus'' Legalov, 2013 is a species from the Eocene of Europe found in Baltic amber.Ne ...
'' and one
flea beetle
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Though m ...
were selected as candidates for preliminary testing in the 1990s. Since that time, those studying the candidates have narrowed the list to two or three weevils. Despite the demonstrated effectiveness of ''C. scrobicollis'' and ''C. constrictus'' in field testing, the importation and release of biological control agents such as those has been repeatedly blocked by the USDA's TAG (Technical Advisory Group). In particular, ''C. scrobicollis'', which is
monophagous
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can thrive only in a narrow range of e ...
and has been specifically studied since 2002, continues to be blocked, despite researchers' many petitions for approval.
It is currently estimated that adequate control of garlic mustard can be achieved by the introduction of just two weevils, with ''C. scrobicollis'' being the most important of the two.
[Becker, R., 2017. Implementing Biological Control of Garlic Mustard – Environment and Natural Resources Trust Fund 2017 RFP. http://www.lccmr.leg.mn/proposals/2017/original/107-d.pdf] None of the roughly 76 species that control this plant in its native range has been approved for introduction as of 2018 and federal agencies continue to use more traditional forms of control, such as chemical herbicides.
In North America, the plant offers no known wildlife benefits and is toxic to larvae of certain rarer butterfly species (e.g. ''
Pieris oleracea
''Pieris oleracea'', or more commonly known as the mustard white, is a butterfly in the family Pieridae native to a large part of Canada and the northeastern United States. The nearly all-white butterfly is often found in wooded areas or open pla ...
'' and ''
Pieris virginiensis
''Pieris virginiensis'', the West Virginia white, is a butterfly found in North America in the Great Lakes states, along the Appalachians from New England to Alabama, and in southern Ontario. They are typically found in moist deciduous forests. F ...
'') that lay eggs on the plants, as it is related to native mustards but creates chemicals that they are not adapted to.
Native species, including two stem-mining weevils, a stem-mining fly, a leaf-mining fly, a scale insect, two fungi, and aphids (taxonomic identification for all species is pending) were found attacking garlic mustard in North America. However, their attacks were of little consequence to plant performance or reproduction of garlic mustard.
References
External links
Flora Europaea: ''Alliaria petiolata''Flora of China: ''Alliaria petiolata''Flora of Pakistan: ''Alliaria petiolata''Plants for a Future: ''Alliaria petiolata'' Plant Conservation Alliance's Alien Plant Working Group
Species Profile - Garlic Mustard (''Alliaria petiolata'') National Invasive Species Information Center,
United States National Agricultural Library
The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located ...
. Lists general information and resources for Garlic Mustard.
Most Unwanted – Garlic Mustard (''Alliaria petiolata'') Ontario Invasive Plant Council. Biological information and resources for Garlic Mustard in Ontario.
{{Authority control
Brassicaceae
Flora of Europe
Flora of North Africa
Flora of Western Asia
Flora of Central Asia
Flora of Xinjiang
Flora of Pakistan
Butterfly food plants
Edible plants
Leaf vegetables
Medicinal plants