Gutierrezia microcephala | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Genus: | Gutierrezia |
Species: | G. microcephala |
Binomial name | |
Gutierrezia microcephala | |
Synonyms [1] | |
Synonymy
|
Gutierrezia microcephala is a species of flowering plant in the family Asteraceae known by the common names sticky snakeweed, threadleaf snakeweed, threadleaf broomweed, and smallhead snakeweed. It is a subshrub native to the southwestern United States and northern Mexico, and can be found in arid grassland and desert sand dune habitats. It can be toxic to livestock in large quantities, due to the presence of saponins and high concentrations of selenium.
Gutierrezia microcephala is a small, resinous, perennial desert subshrub that is typically 20 to 60 centimetres (7.9 to 23.6 in) in height and less than 100 centimetres (39 in) in diameter. [2] [3] It is heavily branched, often causing it to be nearly spherical. [3] New shoots and twigs are green to yellow in color, and older parts are brown and woody. [3] The leaves are linear, threadlike, and alternate; 1 to 4 centimetres (0.39 to 1.57 in) long and 0.5 to 2 millimetres (0.020 to 0.079 in) wide. [3] [4] [5] Along with the leaves, the stem tissue is photosynthetic, giving the plant a high photosynthetic capacity. [2] G. microcephala typically flowers July to October, [3] but this can vary depending on the amount of precipitation. [2]
When flowering, the tips of stem branches are occupied by sessile inflorescences of 5 or 6 flowers. The knobby, waxy yellow flower buds open into golden yellow flower heads, each of which has one or two disc florets between 2.2 to 3.3 millimetres (0.087 to 0.130 in) in diameter, and one or two ray florets between 2.1 to 3.5 millimetres (0.083 to 0.138 in) in diameter. [3] The mature plants produce many achene, although most seeds fall within a few metres of the parent plant. [2] This is because the plant grows a very small pappus, which makes wind-borne seed distribution very inefficient. [2]
Gutierrezia microcephala, a native North American plant, is found throughout the southwestern United States (from California east as far as Texas and Colorado) and northern Mexico (from Baja California to Tamaulipas, Veracruz, and Zacatecas). [1] [6] [7] It occurs in a variety of ecoregions, such as arid grasslands, chaparral, sand dunes, and oak or oak-pine woodlands. [3] [4] [6] G. microcephala is primarily found in well-drained sandy, gravelly, or rocky soils, and is often found in intermittently dry creeks or on the adjacent slopes. [2] It often predominates on shallow, rocky soil, where grasses are not well established. [2]
Gutierrezia microcephala was used by the Native Americans for various reasons. [8] The Cahuilla used an infusion of the plant as a gargle or placed the plant in their mouths as a toothache remedy. The Hopi and Tewa both used the plant as a carminative, as prayer stick decorations, and for roasting sweet corn, and the Navajo applied a poultice of the plant to the back and legs of horses for unknown reasons. [9] The Zuni steeped the flower heads in boiling water and used the tea as a diuretic, tonic, and sweat-inducer, and also used the plant as an indicator of water. [10]
Gutierrezia microcephala is of little known use to wildlife, and is generally uneaten by livestock except when other forage is unavailable. [10] [11]
Gutierrezia microcephala can be toxic to livestock, especially when grown in sandy soil. [11] Toxicity is due to the presence of saponins, alkaloids, terpenes, and flavonols, [12] as well as high concentrations of selenium; [13] G. microcephala plants have been found to contain selenium levels of 1287 ppm. [14] Toxicity symptoms include abortion and death; [11] [15] as little as 9 kilograms (20 lb) of fresh G. microcephala consumed by cattle in seven days can cause abortions, and in cattle, sheep, and goats consuming ten to twenty percent of their body weight in two weeks can cause death. [16]
Gutierrezia microcephala is one of the most widespread and damaging rangeland weeds, [17] and is an indicator of overgrazed or disturbed rangelands. [11] The herbicides picloram and triclopyr have been found to give satisfactory control, with control lasting at least 5 to 7 years with proper grazing management. [11] Biological control has also been studied, with a combination of an Argentinean root-boring weevil, Heilipodus ventralis, and an Argentinean moth root-borer, Carmenta haematica , found to be an effective method of control. [17]
Fire kills or severely damages G. microcephala, allowing controlled burns to be used in the management of its populations. [18] Burns must be done carefully, as G. microcephala may recolonize burned sites if moisture conditions and competition is favorable, giving mixed success for prescribed burns. [18] Burns can be limited by insufficient amounts fine fuel; if there is enough fine fuel, burns are generally effective if fuel moisture and relative humidity are low, the air temperature is between 24–32 °C (75–90 °F), and there is a gentle breeze. [18]
Selenium is a chemical element; it has the symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium.
Bromus tectorum, known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, southern Russia, Japan, South Africa, Australia, New Zealand, Iceland, Greenland, North America and western Central Asia. In the eastern US B. tectorum is common along roadsides and as a crop weed, but usually does not dominate an ecosystem. It has become a dominant species in the Intermountain West and parts of Canada, and displays especially invasive behavior in the sagebrush steppe ecosystems where it has been listed as noxious weed. B. tectorum often enters the site in an area that has been disturbed, and then quickly expands into the surrounding area through its rapid growth and prolific seed production.
Gutierrezia is a genus of flowering plants in the family Asteraceae, native to western North America and western South America. Plants of this genus are known generally as snakeweeds or matchweeds. Some species have been called greasewood. They are annual or perennial plants or subshrubs with yellow or white flowers.
Senecio flaccidus, formerly recorded as Senecio douglasii, member of the daisy family and genus Senecio also known as threadleaf ragwort, is a native of the southwestern Great Plains of North America.
Gutierrezia californica is a North American species of flowering plant in the family Asteraceae known by the common names San Joaquin snakeweed and California matchweed. It is native to California and Arizona in the United States and Baja California in Mexico. It grows in sunny sandy or rocky areas in grasslands, scrub, or open woodlands.
Gutierrezia sarothrae is a species of flowering plant in the family Asteraceae known by the common names broom snakeweed, broomweed, snakeweed, and matchweed. It is a subshrub native to much of the western half of North America, from western Canada to northern Mexico, and can be found in a number of arid, grassland, and mountain habitats. It can be toxic to livestock in large quantities, due mainly to the presence of saponins.
Thurovia is a genus of Texan plants in the tribe Astereae within the family Asteraceae.
Astragalus holmgreniorum is a rare species of milkvetch known by the common names Holmgren milk-vetch and paradox milk-vetch. It is native to a tiny section of desert shrub woodland on the border between Utah and Arizona, in the far northern Mojave Desert. There are six populations remaining. It is a federally listed endangered species.
Pediocactus bradyi is a very rare species of cactus known by the common names Brady's pincushion cactus, Brady's hedgehog cactus, and Marble Canyon cactus. It is endemic to Arizona in the US, where it is restricted to Marble Canyon in Coconino County, though its exact distribution is not generally advertised due to poaching concerns. It is limited to a specific type of soil, it has a small distribution, and the species is threatened by a number of human activities. This has been a federally listed endangered species of the United States since 1979.
Sclerocactus glaucus is a rare species of cactus known by the common name Colorado hookless cactus. It is endemic to Colorado in the United States, where it is known only from the area between Grand Junction and Montrose. It is a federally listed threatened species.
Townsendia aprica is a rare species of flowering plant in the family Asteraceae known by the common name Last Chance Townsend daisy. It is endemic to Utah in the United States, where it is known from three counties. It faces a number of threats and it is a federally listed threatened species of the United States.
Chrysothamnus molestus is a species of flowering plant in the family Asteraceae known by the common names Arizona rabbitbrush, Tusayan rabbitbrush, disturbed rabbitbrush, and stickyfruit low rabbitbrush. It is endemic to the State of Arizona in the southwestern United States, where it is known from Coconino, Apache, and Navajo Counties.
Astragalus ripleyi is a species of flowering plant in the legume family known by the common name Ripley's milkvetch. It is native to southern Colorado and northern New Mexico in the United States.
Gutierrezia texana is a North American species of flowering plant in the family Asteraceae known by the common name Texas snakeweed. It is native to the south-central United States and northern Mexico as far south as Guanajuato and Hidalgo.
Trifolium friscanum is a rare species of flowering plant in the legume family known by the common name Frisco clover. It is endemic to the US state of Utah, where it is known only from Beaver and Millard Counties. It is found growing on the San Francisco Mountains, Beaver Lake Mountains, Wah Wah Mountains and Tunnel Springs Mountains. Most individuals live in the San Francisco Mountains, where the highest point is called Frisco Peak. It was originally described as a variety of Trifolium andersonii in 1978, but was elevated to species status in 1993. It occurs over 250 km (160 mi) away from the nearest T. andersonii.
Greasewood is a common name shared by several plants:
Gutierrezia arizonica is a North American species of flowering plant in the family Asteraceae known by the common name Arizona snakeweed. It is native to Arizona in the United States and Sonora in northwestern Mexico.
Gutierrezia petradoria is a species of flowering plant in the family Asteraceae known by the common names San Pedro snakeweed and goldenrod snakeweed
Gutierrezia wrightii is a North American species of flowering plant in the family Asteraceae known by the common name Wright's snakeweed. It is native to the southwestern United States and northwestern Mexico.
Asteromyia gutierreziae is a species of gall midges in the family Cecidomyiidae.