is a species of flowering plant in the family
Amaranthaceae
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 ...
. It is known by various
common names
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contra ...
such as prickly Russian thistle, windwitch, or common saltwort. It is widely known simply as tumbleweed because in many regions of the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, it is the most common and most conspicuous plant species that produces
tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...
s. Informally, it also is known as "'
salsola
''Salsola'' is a genus of the subfamily Salsoloideae in the family Amaranthaceae. The genus ''sensu stricto'' is distributed in central and southwestern Asia, North Africa, and the Mediterranean. A common name of various members of this genus and ...
", which was its
generic name until 2007.
[
For a brief phase during its youth, it may be grazed but afterwards becomes too spiny and woody to be edible to most wildlife and livestock (if it is not processed first). Mature specimens are often more than a ]meter
The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...
in diameter. As its fruits mature, the diaspore
Diaspore , also known as diasporite, empholite, kayserite, or tanatarite, is an aluminium oxide hydroxide mineral, α-AlO(OH), crystallizing in the orthorhombic system and isomorphous with goethite. It occurs sometimes as flattened crystals, bu ...
of the plant dies, dries, hardens, and detach from its root. This detached anatomical part of is called a tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...
, which is why is colloquially called "tumbleweed" (although there are many other plant species that also produce tumbleweeds). Once mature, dry, and detached from the plant, this tumbleweed will tumble (i.e. roll) due to the force of the wind. As this dead structure tumbles in the wind, it gradually degrades and falls apart, thereby spreading (possibly as many as 200,000) seeds. If it happens to come to rest in a wet area then it can germinate
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...
rapidly, even with very small amounts of moisture. It has a high tolerance of salinity and can successfully compete with many native plants in certain environments, such as along sea beaches and especially in grassland, desert, or semiarid
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...
regions. Consequently, it now occupies a wide variety of habitats. Native to Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
, has proven to be highly invasive as an introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
and rapidly became a common ruderal
A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...
weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
of disturbed habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
s throughout the world. The tumbleweed's tumbling is known to damage non-native plants and environments and its highly flammable nature also sometimes helps wildfire
A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...
s spread, especially during windy conditions. An ignited tumbleweed may spread a fire across firebreak
A firebreak or double track (also called a fire line, fuel break, fireroad and firetrail in Australia) is a gap in vegetation or other combustible material that acts as a barrier to slow or stop the progress of a bushfire or wildfire. A firebre ...
s and may even ignite buildings or structures that it stops against.
Taxonomy
Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
originally described the species as . It was given its current name by Giovanni Antonio Scopoli
Giovanni Antonio Scopoli (sometimes Latinisation of names, Latinized as Johannes Antonius Scopolius) (3 June 1723 – 8 May 1788) was an Italian physician and natural history, naturalist. His biographer Otto Guglia named him the "first anational ...
.
is native to Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
, but in the 1870s, it appeared in South Dakota
South Dakota (; Sioux language, Sioux: , ) is a U.S. state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota people, Lakota and Dakota peo ...
when flax
Flax, also known as common flax or linseed, is a flowering plant, ''Linum usitatissimum'', in the family Linaceae. It is cultivated as a food and fiber crop in regions of the world with temperate climates. Textiles made from flax are known in ...
seed from Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
turned out to be contaminated with seeds. Although it is the best-known of this group of weeds, and was at first thought to be a single well-defined species, it now is known to have included more than one species plus some hybrids. This has led to taxonomic confusion in dealing with species in the genera and in America. Recent studies show that the population that once was assigned to really includes three or more morphologically similar species that differ in flower size and shape. The group was widely assigned to the family 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 ...
, but the Chenopodiaceae – including the genera and – have since been included in the Amaranthaceae. They now are allocated to the Salsoloideae
The Salsoloideae are a subfamily of the Amaranthaceae, formerly in family Chenopodiaceae.
Description
These are herbs, subshrubs, shrubs and some trees. Stems and leaves are often succulent. The ovary contains a spiral embryo. In most genera ...
, a subfamily of the Amaranthaceae.
Description
is an annual
Annual may refer to:
* Annual publication, periodical publications appearing regularly once per year
**Yearbook
** Literary annual
* Annual plant
* Annual report
* Annual giving
* Annual, Morocco, a settlement in northeastern Morocco
* Annuals (b ...
forb
A forb or phorb is an herbaceous flowering plant that is not a graminoid (grass, sedge, or rush). The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory. Typically these are dicots without woo ...
. In habit
A habit (or wont as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously. , the young plant is erect, but it grows into a rounded clump of branched, tangled stems, each one up to about a metre long. Depending on the plant's genetics and condition, the leaves and stems may be green, red, or striped, and they may be hairless or pubescent The adjective pubescent may describe:
* people or animals undergoing puberty
* plants that are hairy, covered in trichomes
* insects that are covered in setae
In biology, setae (singular seta ; from the Latin word for "bristle") are any of a ...
. The leaves are tipped with spines that in most varieties are so sharp that the plants are best handled with gloves and other suitably protective clothing, though some genetic variants have only a hair at the tip. On the young plant, leaves may be more than 5 cm long, succulent
In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...
and more or less cylindrical
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infini ...
; these juvenile leaves are deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
and drop off as the plant matures. The leaves of the mature plant are persistent, leathery, broader and shorter than the young leaves (seldom more than 1 cm in length), rigid and spine-tipped. They remain on the stem till the plant dies at the end of the season. In the axil
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
of the mature leaf, there are two leaf-like bracts with a flower between them. The flower lacks petals, but is surrounded by a disk of wide, winged sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
s, whitish to pink in color.
Ecology
Reproduction and dispersal
The plant becomes woody as the fruits develop. As they ripen, the plant begins to die, dries out and becomes brittle. In that state the base of the stem breaks off easily, particularly in a high wind. The plant then rolls readily before the wind and disperses its seeds as a tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...
.
A large specimen of may produce some 200,000 seeds.
Invasive potential
has proven to be highly invasive as an introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
and rapidly became a common ruderal
A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...
weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
of disturbed habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
s in many regions of North America, particularly in the 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 ...
. The species also has become 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 ...
in various regions of Central and South America and in parts of Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...
and Australia. It now occupies a wide variety of habitat types in those regions and often is the first or even the only colonizer in conditions where no local species can compete
Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...
successfully. Because of its preference for sand and its tolerance of salinity, it commonly grows along sea beaches as well as in disturbed grassland and desert communities, especially in semiarid
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...
regions.[.]
Edibility
The plant is considered edible when young, and the young shoots can be harvested and eaten. As the plant matures, it becomes too woody, bitter, and spiny to be considered edible. The young shoots can be eaten raw in salads, and are reported to be even more flavorful when cooked as a pot herb. Young plants are also reported as good fodder for livestock. Some varieties of Russian thistle Russian thistle is a common name that can refer to:
* ''Echinops exaltatus'', also known as ''Russian globe thistle'', is a globe thistle native to Eurasia and an invasive species in Eastern Canada and Northern United States.
* ''Kali tragus'', fo ...
can contain above average levels of oxalic acid
Oxalic acid is an organic acid with the systematic name ethanedioic acid and formula . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name comes from the fact that early inve ...
, particularly in older plants, and people who are sensitive to oxalic acid should avoid the genus as it is a severe allergen for some people. People who have adverse reactions to eating spinach
Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either f ...
, which also can have high levels of oxalate
Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl o ...
s, should avoid consumption of Russian thistle.
Ecology and agricultural management
is a ruderal
A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural for example, wildfires or avalanchesor the consequences of human activities, such as construction ( of roads, of buildings, mining, et ...
annual forb
A forb or phorb is an herbaceous flowering plant that is not a graminoid (grass, sedge, or rush). The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory. Typically these are dicots without woo ...
. It germinates rapidly even in very small amounts of moisture in arid conditions. When young it may be grazed freely, but that phase lasts for only a brief period, and generally at a time when other forage
Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...
is relatively plentiful. After this it becomes a weed
A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
in most contexts. One reason is that as they mature most varieties become too spiny and woody for most stock to browse. As its fruits mature, the plant dies, dries and becomes hard and brittle. It is in this state that it is likely to detach from its root and become a tumbleweed. As tumbleweeds go, it is very large, often a metre or more in diameter, spiny, largely inedible to most livestock if unprocessed, and a fire hazard
Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and ef ...
.[; and ] However, in regions where there is plentiful winter rain, the moisture softens both the twigs and the spines, after which hardy breeds of livestock and some wildlife species once again will eat it.
has acquired a bad reputation for its spininess, its woodiness when mature, and its general ecological competitiveness, augmented by its tumbleweed nature, which enables it to spread rapidly over open ground. Prince Gallitzin reported that on the journey out of his native Russia he passed through southwest Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
and found the Imperial government's irrigation project abandoned and the farms deserted, on account of ''K. tragus''. Furthermore Oryol Oblast
Oryol Oblast (russian: Орло́вская о́бласть, ''Orlovskaya oblast''), also known as Orlovshchina (russian: Орловщина) is a federal subjects of Russia, federal subject of Russia (an oblast). Its administrative center is th ...
and Kyiv Oblast
Kyiv Oblast ( uk, Ки́ївська о́бласть, translit=Kyïvska oblast), also called Kyivshchyna ( uk, Ки́ївщина), is an oblast (province) in central and northern Ukraine. It surrounds, but does not include, the city of Kyiv, w ...
were also especially infested. During the past century or more, the majority of the publications that dealt with the topic have discussed its pernicious nature, the increasing threats that the species poses, and how to combat its invasiveness; they largely have ignored its other attributes.
However, even early publications did concede that the plant is of value as a forage in severely arid conditions where few other forage species are viable. As for its harmful competitiveness, most authors emphasised its invasiveness, though some did mention its value in regenerating overgrazed or otherwise abused land.
Apart from its value to domestic cattle and sheep in some regions, is a source of food and shelter for several species of wild life. Its nutritional value is high; it is rich in various minerals, Vitamin A, and phosphorus. It is a minor forage component for bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...
, mule deer
The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer.
Unlike the related whit ...
, and wapiti
The elk (''Cervus canadensis''), also known as the wapiti, is one of the largest species within the deer family, Cervidae, and one of the largest terrestrial mammals in its native range of North America and Central and East Asia. The common ...
. Pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American a ...
eat it with reluctance in drought conditions, but feed on it avidly under rainy conditions, especially in wet years. Prairie dog
Prairie dogs (genus ''Cynomys'') are herbivorous burrowing ground squirrels native to the grasslands of North America. Within the genus are five species: black-tailed, white-tailed, Gunnison's, Utah, and Mexican prairie dogs. In Mexico, p ...
s consume it as a major food wherever they encounter it. Seed-eating birds and small mammals such as rodents
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are nat ...
feed on the seeds.
offers shelter for some wildlife. Medium-sized deer species make some use of it, but it is mainly of value to small mammals and bird species that normally live close to the ground and shelter under bushes.
Some livestock species such as camel
A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. C ...
s and some breeds of stock that are adapted to semi-desert
A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...
conditions will brave the spines when forage becomes scarce. Many goats and some breeds of sheep such as karakul browse the bushes. The plant, like many members of the Amaranthaceae, is rich in high-quality protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
s with a good balance of essential amino acids
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
. The seed even more so.
and many related species, including some that are widely regarded as invasive weeds in other countries, are valued in their regions of origin. They are adapted to inhospitable environments that do not support many other forage species. In Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked cou ...
, for example, stems, fruits, and leaves are nutritious year-round camel feed; sheep and goats prefer it in summer, but also to some extent in autumn and winter. The fruits are important for fattening camels, goats, and karakul sheep; the fruit may partially substitute for concentrates, especially in autumn and winter. In those regions annual species are known as "solyanki"; they are important as drought- and salt-tolerant forage and form a dominant group in the flora and vegetation of the most challenging environments. Some are useful for stabilising shifting sands and for rehabilitation of degraded rangelands such as the saline soil of the red desert of Kyzyl Kum
The Kyzylkum Desert ( uz, Qizilqum, Қизилқум, قىزىلقۇم; kk, Қызылқұм, Qyzylqūm, قىزىلقۇم) is the 15th largest desert in the world. Its name means ''Red Sand'' in Turkic languages. It is located in Central Asia, i ...
. Some of the species also invade ruderal sites or occur as weeds in cultivated fields.
Although still has not won much recognition in contemporary first-world livestock nutrition, this might reflect short memories rather than shortage of evidence for its merits; during the Dust Bowl
The Dust Bowl was a period of severe dust storms that greatly damaged the ecology and agriculture of the American and Canadian prairies during the 1930s. The phenomenon was caused by a combination of both natural factors (severe drought) an ...
era, it was credited with having rescued beef cattle husbandry in North America. The usual hay crops had failed and when all other sources failed farmers fed their cattle on tumbleweed.
''Kali'' management and soil rehabilitation
In spite of the reigning conception that its presence is harmful, is of particular value in rehabilitating certain classes of disturbed land. Often its presence is beneficial, especially when the original topsoil still is present; the species happens not to be host to any mycorrhiza
A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant ...
l fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
, whereas many or most common plants in fact are so adapted. As a result, when mycorrhizae surviving in the topsoil invade roots they tend to kill the tissue, commonly stunting or even killing the plant. When the plant is dead and the mycorrhizae have consumed what they can of its remains, they spread out and infect more plants, beneficially to most desirable grasses and forbs, but to the disadvantage of most of the that had been occupying the soil. They only remain to enrich, mulch and aerate it. This promotes reinvasion of the soil by other plants adapted to forming advantageous symbiotic associations with mycorrhizae. Above the ground, any dead plants that remain standing provide shade that favours other plants' seedlings; plants themselves on the other hand are highly intolerant of shade, being very much adapted to open, barren soil. This apparently complex process tends to repopulate the soil better and faster than killing the with herbicides
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page fo ...
and waiting for apparently more desirable plants to make good the original damage to the soil.
In disturbed sites with no topsoil and therefore few or no mycorrhizae, the population may remain dominant for over a decade. To speed the recovery, it is better to add rich topsoil with plenty of organic material and mycorrhizae than to attack the population. However, it is important not to regard the ecological interrelationships too simplistically; in some cases the presence of the healthy weed plants on a harsh site without mycorrhizae actually seems to facilitate the succession of grass better than where a mycorrhizal inoculum had reduced the population of the . The assumed competitive effect of the should be assessed and monitored in each case. Furthermore, of course, where degraded soil is effectively barren, is better as a pioneer
Pioneer commonly refers to a settler who migrates to previously uninhabited or sparsely inhabited land.
In the United States pioneer commonly refers to an American pioneer, a person in American history who migrated west to join in settling and de ...
population than simply leaving the soil completely barren. grows best on sandy or at least loose-surfaced soil, so it might pay better to rake the soil to encourage invasion for a few years until its presence has mitigated the conditions.
Another factor to bear in mind in dealing with is grazing or, more particularly, overgrazing
Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...
. In regions where competitive vegetation is present together with the , overgrazing may favour the weed, while managing the grazing intensity to favour the desired plants may be the most economical, and in the long term, the most effective way of dealing with its overgrowth. A good example was in controlling troublesome on Bighorn Sheep
The bighorn sheep (''Ovis canadensis'') is a species of sheep native to North America. It is named for its large horns. A pair of horns might weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates three distinct subspec ...
Winter Ranges in Jasper National Park
Jasper National Park is a national park in Alberta, Canada. It is the largest national park within Alberta's Rocky Mountains spanning . It was established as a national park in 1930 and declared a UNESCO World Heritage Site in 1984. Its locatio ...
by proper management of grazing intensity.[Tim M. Antill, M. Anne Naeth, Edward W. Bork, and Alan L. Westhaver. Russian Thistle (Salsola tragus L.) Control on Bighorn Sheep Winter Ranges in Jasper National Park. Natural Areas Journal 2012 32 (4), 391-397]
''Kali'' and phytoremediation
A special class of soil mitigation is phytoremediation
Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronomi ...
, in which the removal and accumulation of toxic elements from soils by suitable management of plant growth is a major component. Because such soil situations as mine dumps tend to be extreme examples of disturbed sites, and often are of fine texture, species show promise for certain classes of such work. Simply by growing there in high density they can play a valuable role in phytostabilization by reducing wind erosion and similar processes that promote the spread of pollution. The dry tumbleweed material also has been used as a mulch
A mulch is a layer of material applied to the surface of soil. Reasons for applying mulch include conservation of soil moisture, improving fertility and health of the soil, reducing weed growth and enhancing the visual appeal of the area.
A m ...
on replanted coal mine spoils in Arizona.
However, these plants also show promise as hyperaccumulator A hyperaccumulator is a plant capable of growing in soil or water with very high concentrations of metals, absorbing these metals through their roots, and concentrating extremely high levels of metals in their tissues. The metals are concentrated a ...
s for phytoremediation by phytoextraction Phytoextraction is a subprocess of phytoremediation in which plants remove dangerous elements or compounds from soil or water, most usually heavy metals, metals that have a high density and may be toxic to organisms even at relatively low concentra ...
, the absorption of certain classes of toxic or at least undesirable chemicals from the soil. Commonly these are ions of heavy metals, such as cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...
(Cd(II)), chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
(both Cr(III) and Cr(VI)), lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
(Pb(II)), arsenic
Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
(both As(III) and As(V)), copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...
(Cu(II)), nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
(Ni(II)), and zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...
(Zn(II)). Such processes have been studied in for all those ions,[Guadalupe de la Rosa, "Application of modern spectroscopic techniques to study heavy metal accumulation and uptake mechanisms in tumbleweed (Salsola kali)", 2005. ETD Collection for University of Texas, El Paso. Paper AAI3167940]
/ref> and others such as iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
and cobalt
Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, pr ...
. proved to be an active absorber of all those ions, plus some others, and it may well be a hyperaccumulator of both copper and cadmium. It certainly accumulated lead and arsenic very actively and also chromium in the most toxic hexavalent form.
It is not yet clear that would be a useful species for commercial phytoextraction, either for phytoremediation or for phytomining
Phytoremediation technologies use living plants to clean up soil, air and water contaminated with hazardous contaminants. It is defined as "the use of green plants and the associated microorganisms, along with proper soil amendments and agronomi ...
, but there are genetic variables that could, in principle, be selected for. For instance, the ions the plant species absorb are variously bound or chelate
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands are ...
d by organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are rel ...
groups such as oxalate
Oxalate (IUPAC: ethanedioate) is an anion with the formula C2O42−. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate (Na2C2O4), and several esters such as dimethyl o ...
, or by thiol group
In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl gro ...
s, among others. Some, such as arsenate
The arsenate ion is .
An arsenate (compound) is any compound that contains this ion. Arsenates are salts or esters of arsenic acid.
The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As(V).
Arsenate resem ...
, pass through phosphate metabolic processes before being bound by sulfur groups.
However, a plant that has absorbed some of the levels of toxic substances (e.g., arsenic, lead, or cadmium) that the species can accumulate probably would not be suitable for food or fodder. Thus, phytoextraction sites would have to be protected from livestock.
Prospects for genetic improvement
Such considerations have led some workers to recommend that the plant be actively exploited for its very attractive merits. Frustratingly however, the plant in the wild is very variable; apart from its intrinsic genetic variability, invasive populations have hybridised extensively with other species of that apparently were imported at the same time, and to some extent the genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
hybridises in the countries of its origin as well. Apart from such sources of variability, there are considerable variations in ploidy
Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Sets of chromosomes refer to the number of mat ...
. The unpredictability of the merits of wild strains may frustrate farmers who have tried the species and found that seeds from wild plants do not produce crops that live up to their hopes, so they tend to abandon the attempts.
However, in spite of the associated difficulties, the plants' genetic variability does imply opportunities for genetic improvement. The presence of tetraploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains ...
s and hexaploids improves the prospects for new variants to be established in the population. The species and its hybrids and variants have attracted attention as valuable prospects for selective breeding for various agricultural purposes. The most desirable and the most undesirable genetically determined attributes have turned out to assort independently, which is a necessary condition for efficient selection of independent characters, so that for example, one can select breeding stock with desirable attributes, without being unable to select for the absence of undesirable attributes. One could select say, lines rich in protein, but without spines.
To appreciate the implications of the variability, consider the following isolated examples of variability in key attributes of dry matter, as found in some 70 samples collected from the south-western United States:
These figures are not the only important genetically determined variables, but they are illustrative. Note that the high values in the list differ from the corresponding low values by factors ranging from a little over 2 in the case of acid-detergent fiber, to more than 60 for nitrate content. Other physical variables such as size and spininess also diverge markedly. As already noted, in many regions the plant passes through its most palatable and vulnerable phase before the need for forage begins to become more pressing. However, some strains are not spiny, so that there is scope for breeding lines that are useful throughout most of the season. Note too that while some variables, such as protein content, should preferably be as high as possible, others, while harmless or even beneficial at low levels, may be undesirable or even dangerous at the highest recorded levels. For example, rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants and the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. The rumen's microbial favoring environment allow ...
flora in ruminant
Ruminants (suborder Ruminantia) are ungulate, hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principally ...
s metabolise
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...
nitrate and oxalate profitably at modest concentrations, but if the concentration overwhelms their metabolic capacity, the unprocessed ions may poison livestock. Strains of plants selected for modest levels of such content can therefore be fed without strict precautions, but the toxic components of other strains would best be diluted by mixing fodder with other, safer forage, or treating it with mitigating agents. For example, excess soluble oxalate can be precipitated by adding lime to the fodder; precipitated oxalate is harmless. Digestibility also varied in this study, but the digestibility of was in general greater than the digestibility of grasses.
Another desirable trait of and several related species, is that it is salt-tolerant
Halotolerance is the adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles a ...
in arid and sandy environments. In fact, it seems to do best at salt levels that – though modest – are far too high for most crops to tolerate. Growing the plant in environments too saline for most other forage species, even high enough to stress the , actually increases some of its merits as a forage. In particular, it increases total nitrogen content but reduces some (possibly harmless) levels of potentially toxic substances such as soluble oxalate and nitrate.[Fowler, James L. Hageman, James H. Moore, Kenneth J. Suzukida, Margaret. Assadian, Hamid. Valenzuela, Mario. Salinity effects of forage quality of Russian Thistle. Journal of Range Management. 45:559-563 November 1992]
Other problems and products
One of the unwelcome attributes of is that it commonly presents a fire hazard, firstly because it is flammable once it is thoroughly dry, partly as a result of its nitrate content, which may be very high, sometimes over 6% dry weight
Vehicle weight is a measurement of wheeled motor vehicles; either an actual measured weight of the vehicle under defined conditions or a gross weight rating for its weight carrying capacity.
Curb or kerb weight
Curb weight (U.S. English) or kerb ...
.[Hageman, James H. Fowler, James L. Suzukida Margaret. Salas, Virginia. Captain, Roxanne Le. Analysis of Russian thistle (Salsola species) selections for factors affecting forage nutritional value. New Mexico State University, 1987]
/ref> Secondly, in a season in which the growth has been heavy, high winds often accumulate shocking tangles of the tumbleweeds, covering entire buildings or trapping vehicles so completely as to prevent unaided escape, particularly in the event that the dry material ignites. When they bank up against wire fences, the force of the wind against the mass is likely to damage the fence, and so will the fire if the mass ignites. In wildfire
A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...
conditions in open country, strong winds often blows burning tumbleweeds across firebreak
A firebreak or double track (also called a fire line, fuel break, fireroad and firetrail in Australia) is a gap in vegetation or other combustible material that acts as a barrier to slow or stop the progress of a bushfire or wildfire. A firebre ...
s, frustrating standard fire control
Fire control is the practice of reducing the heat output of a fire, reducing the area over which the fire exists, or suppressing or extinguishing the fire by depriving it of fuel, oxygen, or heat (see fire triangle). Fire prevention and control i ...
measures. When the burning weeds are stopped by buildings or stacks, they ignite such objects more effectively than any other tumbleweed on the open plains, being compact and woody at maturity, as well as highly flammable.[Dewey, Lyster Hoxie. The Russian Thistle. Washington Government Printing Office, 189]
/ref>
The complex has been associated with presumably allergic sensitivities to various parts of the plant. Many people develop skin rashes and assorted other reactions after exposure to the plant. Scratches and abrasions from spines or hard stems from the plant may cause itching or inflamed skin.[Orloff, S. B.; Cudney, D. W.; Elmore, C. L.; DiTomaso, J. M. Pest Notes: Russian Thistle UC ANR Publication 7486. UC Statewide IPM Program, University of California, Davis, CA 95616] Furthermore, fertilisation in this genus plus most species in the entire family is at least partly by wind pollination
Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous plan ...
, and in some regions their pollen load may represent up to 5% of the total pollen load, causing many allergic sensitizations.[Carnés, J., Fernández-Caldas, E., Marina, A., Alonso, C., Lahoz, C., Colás, C. and Lezaun, A. (2003), Immunochemical characterization of Russian thistle (Salsola kali) pollen extracts. Purification of the allergen Sal k 1. Allergy, 58: 1152–1156. doi: 10.1034/j.1398-9995.2003.00269.x]
Some species also are harvested for the extraction of compounds such as the alkaloid “ salsolin”, used in the preparation of certain pharmaceuticals.
In its dried, tumbleweed form, the plant is generally difficult to work with, being springy, spiny, flammable and brittle, but like many other dried vegetable materials, primarily grass straw, it has been baled and used in building houses in regions such as parts of Nebraska, where not only timber, but even sod
Sod, also known as turf, is the upper layer of soil with the grass growing on it that is often harvested into rolls.
In Australian and British English, sod is more commonly known as ''turf'', and the word "sod" is limited mainly to agricult ...
, often was in short supply.
Experimental work in Turkey suggests that chopped, milled and briquette
A briquette (; also spelled briquet) is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, peat, or paper) used for fuel and kindling to start a fire. The term derives from the French word '' ...
d, optionally with the addition of other organic wastes such as sawdust and nut shells, the woody tumbleweed waste makes a usable rural fuel.
In its freshly sprouted form, before it has developed spines or unpleasantly tough fibres, has been recommended as a 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 ...
, stir-fry
Stir frying () is a cooking technique in which ingredients are fried in a small amount of very hot oil while being stirred or tossed in a wok. The technique originated in China and in recent centuries has spread into other parts of Asia and th ...
, or potherb
Leaf vegetables, also called leafy greens, pot herbs, vegetable greens, or simply greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. Leaf vegetables eaten raw in a salad can be called salad gre ...
for human consumption. Such dishes would be harmless in modest quantities or if the strain used has a low oxalate and nitrate content. as a salad
/ref>
Gallery
File:LightDeepPinkTumbleweed.JPG, Two bushes, fruiting light pink and deep pink.
File:PinkRedRussianThistleBlossums.JPG, Close-up of fruiting bushes
File:Tumbleweed 038.jpg, in autumn.
File:Starr 050525-7030 Salsola tragus.jpg, on the Hawaiian Island
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Ku ...
of Kahoʻolawe
Kahoolawe (Hawaiian: ), anglicized as Kahoolawe (), is the smallest of the eight main volcano, volcanic islands in the Hawaiian Islands. Kahoolawe is located about southwest of Maui and also southeast of Lanai, Lānaʻi, and it is long by wide ...
.
See also
* Oppositeleaf Russian thistle
* Russian globe thistle
* Salsola
''Salsola'' is a genus of the subfamily Salsoloideae in the family Amaranthaceae. The genus ''sensu stricto'' is distributed in central and southwestern Asia, North Africa, and the Mediterranean. A common name of various members of this genus and ...
* Tumbleweed
A tumbleweed is a structural part of the above-ground anatomy of a number of species of plants. It is a diaspore that, once mature and dry, detaches from its root or stem and rolls due to the force of the wind. In most such species, the tumble ...
References
External links
Jepson Manual Treatment -
Washington Burke Museum -
- U.C. Photo gallery
{{Taxonbar, from1=Q1754334, from2=Q21715260
Amaranthaceae
Barilla plants
Edible plants
Flora of Lebanon
Flora of Russia
Tumbleweeds