Aegilops triuncialis subsp. triuncialis [= Aegilops triuncialis var. triuncialis]

Barbs of the barbed goatgrass, containing seeds, that become embedded into animals, humans, and vehicles that aid in the spread of the plant.^[1]

Effect of the herbicide, glyphosate, on weeds.^[2][3]

Aegilops triuncialis, or barbed goatgrass, is a winter annual grass species of the Poaceae family.^[1] Barbed goatgrass grows to be about 8 to 16 inches tall with few to many stalks.^[4] The tops of the stalks contain sharp, rigid blades and barbs, which contain the seeds.^[2] When the grass matures, the barbs fall off the stalks to germinate on the ground.^[2] This species is native to many areas in Eastern and Mediterranean Europe and Western Asia.^[2] It is considered an introduced, invasive species in North America, mainly in the Western coast of the United States.^[4] In its native lands, the grass thrives in mainly rocky, serpentine soil, but also does well in grasslands.^[5]

As an invasive species[edit]

Barbed goatgrass was introduced to North America in the 20th century from Mediterranean Europe and Western Asia.^[2] Barbed goatgrass has been found in California, Oregon, Nevada, and the New England area, but the grass has most heavily impacted California.^[6] Barbed goatgrass was introduced to the California area with the trade of Mexican cattle in the early 20th century.^[6] Barbed goatgrass is a fast-growing, rapidly spreading invasive species mainly in grasslands, pastures, and ranches. It is listed as a noxious weed by California Department of Food and Agriculture.^[7] Because of its fast, invasive growing patterns, barbed goatgrass creates a monoculture, killing the other plants in its area.^[2] The invasive nature of barbed goatgrass is causing a decrease in species diversity, and a decrease in forage.^[2] Most grazing animals tend to avoid barbed goatgrass because they do not like the taste of it, allowing the grass to take over the other grasses and grains consumed by the animals.^[6] The barbs on the grass containing the seeds become attached easily to animal fur, human clothing, and vehicles; this movement allows the seeds to become more widely dispersed over the area.^[2]

Control methods[edit]

The most important component in the control of barbed goatgrass is early detection. When found in small isolated areas, it can be more effectively taken care of. ^[2]Controlled burning is one method being used by the University of California in small areas to try and control the amount of barbed goatgrass.^[2] To be most effective, multiple burns had to be put in place in the isolated area over two years to more fully rid the area of the grass. After the burns, many native species were able to live in the small area once again.^[2][7]

Another method being used by both University of California and the Weed Science Society of America to control barbed goatgrass is the spraying of a chemical, glyphosate. Used over a two year period in small areas, glyphosate was able kill barbed goatgrass and all its seedlings. ^[2][3] Although the chemical is effective in killing barbed goatgrass, it also kills the other plants in the area.^[2][3]Aminocyclopyrachlor, a new experimental chemical is also being used to control barbed goatgrass by University of California's Weed Science department. It has shown to be extremely effective, but aminocyclopyrachlor is not a registered herbicide, so widespread use is not allowed yet.^[8]

Mowing of the grass is another method used to control. It allows the grass to be cut before maturing and developing seeds to reproduce, but it is not as effective as the other methods because the deep and established root system of the barbed goatgrass is still in place and can grow again.^[2][3]

Impact on humans[edit]

Although there are many ways to control the growth of barbed goatgrass, a real solution has not been found in its widespread prevention. Barbed goatgrass cross breeds with different types of wheat, causing the grain to become infertile and unusable for harvest, which hurts the economy of the rural California areas.^[4] It can also seriously harm grazing animals by the barbs becoming embedded in their nose, mouth, and eyes, causing farmers and ranchers extra expenses.^[2] It reduces the amount of forage in the area, decreases biodiversity and overall degrades the ecosystem it resides in.^[2] Studies of the University of California also show that if climate change increased the amount of precipitation in the area, the amount of barbed goatgrass may increase, destroying even more of its ecosystem.^[9] Its rapid growth and resiliency against control methods prove that barbed goatgrass is an invasive species that could cause many more problems to the agriculture of California and possibly many other areas if it is not taken care of soon.^[2]