Halogeton glomeratus
Encyclopedia
Halogeton glomeratus is a species of flowering plant in the amaranth family
known by the common names saltlover, Aral barilla, and halogeton. It is native to Russia and China, but the plant is probably better known in the western United States, where it is an introduced species
and a notorious noxious weed. This annual herb is a hardy halophyte
, thriving in soils far too saline to support many other plants. It also grows in alkali soils such as those on alkali flats and disturbed, barren habitat. It can be found in sagebrush
and shadscale
habitat, and it grows well in areas with cold winters.
This plant produces a usually erect stem with several curving branches up to about 25 centimeters (10 in) tall. It has a taproot
reaching up to half a meter deep in the soil and many lateral roots. The branches are lined with narrow, fleshy, blue-green leaves each up to about 2 centimeters long tipped with stiff bristles. The inflorescence
s are located all along the stem branches next to the leaves. Each inflorescence is a small cluster of tiny bisexual and female-only
flowers accompanied by waxy bract
s. The winged, membranous flowers surround the developing fruit, which is all that remains on the plant when it is ripe, the leaves and flower parts having fallen away. The fruit is a pale cylindrical utricle. The plant produces large amounts of seeds, which are dispersed
by many vehicles, including human activity, animals (including ant
s), water flow, wind, and by being carried on the dry plant when it breaks off at ground level and rolls away as a tumbleweed
. The seeds have the ability to germinate
within one hour after being exposed to water.
This herb is a pest on rangelands in the western United States. It has a high oxalate
content, with up to 30% of the plant's dry weight made up of oxalate crystals, making it toxic
to livestock
that graze on it. It is especially toxic to sheep, which can be fatally poisoned by as little as twelve ounces (350 g) of the plant. Halogeton was first recognized as a danger to sheep in the 1940s after a rancher lost a herd of 160 sheep to poisoning. The oxalate causes acute hypocalcemia in the sheep, causing them to stagger, spasm
, and finally die. Ingestion of a fatal dose of the plant can cause death in a sheep in under 12 hours. Ranchers often provide calcium-supplemented
feed to sheep grazing on halogeton-infested land. Sheep are also able to adapt
to halogeton in their diets over time, becoming sick from it less easily, and since it is hardly palatable they tend to avoid it in the first place when possible.
Halogeton is also destructive to the land of the American west because its excretion of mineral salts makes it harder for other plants to grow where it occurs. The growth of the plant is controlled by introducing certain native plants, such as immigrant kochia
(Kochia prostrata) and crested wheatgrass (Agropyron cristatum
), which compete
successfully with halogeton. Grazing
practices are changed to assure that land is not denuded, since land which is disturbed by overgrazing
is susceptible to halogeton invasion.
Amaranthaceae
The flowering plant family Amaranthaceae, the Amaranth family, contains about 176 genera and 2,400 species.- Description :Most of these species are herbs or subshrubs; very few are trees or climbers. Some species are succulent....
known by the common names saltlover, Aral barilla, and halogeton. It is native to Russia and China, but the plant is probably better known in the western United States, where it is an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and a notorious noxious weed. This annual herb is a hardy halophyte
Halophyte
A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora . Relatively few plant species are...
, thriving in soils far too saline to support many other plants. It also grows in alkali soils such as those on alkali flats and disturbed, barren habitat. It can be found in sagebrush
Sagebrush
Sagebrush is a common name of a number of shrubby plant species in the genus Artemisia native to western North America;Or, the sagebrush steppe ecoregion, having one or more kinds of sagebrush, bunchgrasses and others;...
and shadscale
Atriplex
Atriplex is a plant genus of 100-200 species, known by the common names of saltbush and orache . The genus is quite variable and widely distributed. It includes many desert and seashore plants and halophytes, as well as plants of moist environments...
habitat, and it grows well in areas with cold winters.
This plant produces a usually erect stem with several curving branches up to about 25 centimeters (10 in) tall. It has a taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
reaching up to half a meter deep in the soil and many lateral roots. The branches are lined with narrow, fleshy, blue-green leaves each up to about 2 centimeters long tipped with stiff bristles. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
s are located all along the stem branches next to the leaves. Each inflorescence is a small cluster of tiny bisexual and female-only
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
flowers accompanied by waxy bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s. The winged, membranous flowers surround the developing fruit, which is all that remains on the plant when it is ripe, the leaves and flower parts having fallen away. The fruit is a pale cylindrical utricle. The plant produces large amounts of seeds, which are dispersed
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...
by many vehicles, including human activity, animals (including ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s), water flow, wind, and by being carried on the dry plant when it breaks off at ground level and rolls away as a tumbleweed
Tumbleweed
A tumbleweed is the above-ground part of a plant that, once mature and dry, disengages from the root and tumbles away in the wind. Usually, the tumbleweed is the entire plant apart from the roots, but in a few species it is a flower cluster. The tumbleweed habit is most common in steppe and desert...
. The seeds have the ability to germinate
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
within one hour after being exposed to water.
This herb is a pest on rangelands in the western United States. It has a high oxalate
Oxalate
Oxalate , is the dianion with formula C2O42− also written 22−. Either name is often used for derivatives, such as disodium oxalate, 2C2O42−, or an ester of oxalic acid Oxalate (IUPAC: ethanedioate), is the dianion with formula C2O42− also written (COO)22−. Either...
content, with up to 30% of the plant's dry weight made up of oxalate crystals, making it toxic
Toxin
A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...
to livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
that graze on it. It is especially toxic to sheep, which can be fatally poisoned by as little as twelve ounces (350 g) of the plant. Halogeton was first recognized as a danger to sheep in the 1940s after a rancher lost a herd of 160 sheep to poisoning. The oxalate causes acute hypocalcemia in the sheep, causing them to stagger, spasm
Spasm
In medicine a spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. It is sometimes accompanied by a sudden burst of pain, but is usually harmless and ceases after a few minutes...
, and finally die. Ingestion of a fatal dose of the plant can cause death in a sheep in under 12 hours. Ranchers often provide calcium-supplemented
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
feed to sheep grazing on halogeton-infested land. Sheep are also able to adapt
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
to halogeton in their diets over time, becoming sick from it less easily, and since it is hardly palatable they tend to avoid it in the first place when possible.
Halogeton is also destructive to the land of the American west because its excretion of mineral salts makes it harder for other plants to grow where it occurs. The growth of the plant is controlled by introducing certain native plants, such as immigrant kochia
Kochia
Kochia is a synonym of the genus Bassia, that belongs to the subfamily Camphorosmoideae of family Amaranthaceae.Two american species traditionally included in Kochia are now in genus Neokochia: Neokochia americana and Neokochia californica....
(Kochia prostrata) and crested wheatgrass (Agropyron cristatum
Agropyron cristatum
Agropyron cristatum is a species in the Poaceae family. This plant is often used as forage and erosion control...
), which compete
Competition (biology)
Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource used by both is required. Competition both within and between species is an important topic in ecology, especially community ecology...
successfully with halogeton. Grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
practices are changed to assure that land is not denuded, since land which is disturbed by overgrazing
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, or by overpopulations of native or non-native wild animals.Overgrazing reduces the...
is susceptible to halogeton invasion.