Scientific Name: Halogeton glomeratus
Distribution: Western United States
Type of Poison: Sodium oxalate
Signs of Poisoning:
Growth Characteristics: Halogeton is a small, fast-growing forb, growing 3 to 12 inches in height. Stems red when young, turning yellow to white with maturity. Stems are branched from base, spreading first, and then growing vertically. Flowers July to September, and reproduces from seeds.
Flowers/Inflorescence: Small and inconspicuous, in leaf axils. Can be unisexual or complete.
Fruits/Seeds: Reproduces from two types of seed: A black seed, with yellowish or reddish fan-like wings and similar to a snail coil, and a brown wingless seed. The black seed germinates quickly, and the brown seed has delayed germination. Seeds are often very numerous, forming a mass from the ground to the tip of the leaves. Brown seeds can remain viable in the soil for 10 years or more.
Leaves: Alternate, simple, fleshy, and tubular. Leaves bluish-green. Has a small hair at the end of the leaves. Leaves resemble a small sausage with a sharp point.
Halogeton often grows along railroad beds, roads, and sheep trails and in places where the soil has been disturbed. Dense stands are found on burned-over areas, overgrazed ranges, dry lake beds, and abandoned dry farms. It thrives in the saline soils of colder semiarid regions - especially where native plant cover is thin; however, halogeton lacks the capacity to compete with vigorous perennial plants and the more aggressive annuals.
Seeds are spread by wind, water, animals, and vehicles.
Halogeton is a prolific seed producer. New plants established from February to mid-August produce a seed crop before the growing season ends in November.
Moisture and warm temperatures cause seed to germinate. Seeds may remain viable in the soil for 10 years or longer.
Sheep can tolerate large amounts of halogeton if they eat other forage at the same time. Most losses occur when hungry animals are allowed to graze in heavy stands of halogeton.
The toxic substance in halogeton is contained in the leaves and other aboveground parts of the plant. It is dangerous at all times, and becomes more toxic as the growing season advances. About 12 ounces of halogeton will kill a sheep that has been without feed for a day or longer; 18 ounces are required to kill a sheep that has been feeding on other forage. The first signs of halogeton poisoning occur 2 to 6 hours after an animal eats a fatal amount; death usually occurs in 9 to 11 hours.
Livestock losses may be reduced by maintaining range that supports good forage and by proper management of animals on halogeton-infested ranges. Supplemental feeding helps prevent halogeton poisoning when animals trail through or graze infested areas.
Do not introduce livestock into areas heavily infested with halogeton unless it can be done slowly to allow time for adaptation to the toxin. This can be accomplished by grazing plants such as shadscale or light stands of halogeton. Livestock should not be allowed to become hungry or thirsty while grazing in areas infested with halogeton. Death in livestock occurs when an animal eats a large amount of halogeton in a short period of time. Animals unloaded in halogeton-infested areas after train or truck shipment may benefit from supplemental feeding before grazing in the halogeton-infested areas. As most grounds around water tanks are infested with halogeton and many livestock graze indiscriminately after watering, livestock deaths often occur after thirsty animals have watered.
Treatments for halogeton poisoning have not been definitely proven to be effective. It has been suggested that oral dicalcium phosphate may reduce oxalate bioavailability by forming insoluble calcium oxalates (3:1 salt to dicalcium phosphate or 5% calcium phosphate in alfalfa pellets). Treatment of hypocalcemia with intravenous calcium gluconate will correct the hypocalcemia but does not reverse the clinical signs or course of the disease.
Because each plant produces vast numbers of seed, some of which may survive for 10 years or more in soil, it is not practical to eradicate any population that has been in existence for 2 years or more. Plants can be held in control by proper use of herbicides, and very small infestations can be eradicated if treated early. Research results indicate that several herbicides are effective for halogeton control. Such treatments may deplete other vegetation resulting in further invasion by halogeton (from seed in the soil) or other pioneer invaders, such as Russian thistle and rabbitbrush. Use the herbicide only to treat small infestations of halogeton. Repeated treatments are necessary for control. Seeding infested areas with crested wheatgrass has been used extensively to crowd out halogeton and improve ranges.
Herbicide control of established stands on saline soils and low precipitation is not recommended. Follow recommended precautions when applying and handling herbicides.
L.F. James, R.F. Keeler, A.E. Johnson, M.C. Williams, E.H. Cronin, and J.D. Olsen. Plants Poisonous to Livestock in the Western States. U.S. Department of Agriculture, Agriculture Information Bulletin 415, 90 pp. 1980.
Pratt, Mindy S. Halogeton. Range Plants of Utah. 2008. Utah State University Extension Service. 24 July 2009. http://extension.usu.edu/rangeplants/htm/halogeton