The problematic grasses commonly referred to as foxtails are confirmed to grow in Texas. The term “foxtail” generally describes the barbed, arrow-shaped seed heads, or awns, of several different grass species that cause mechanical injury to animals. These awns are a significant concern because once they detach and become embedded, their microscopic barbs prevent them from backing out. This means the seed heads only move forward, burrowing deeper into tissue or body cavities.
Foxtail Grass Species Confirmed in Texas
The grasses that pose the greatest hazard are primarily members of the Hordeum genus. Little Barley (Hordeum pusillum) is widespread across the state, producing dense, bristly spikes that dry out and break apart, releasing sharp awns. Foxtail Barley (Hordeum jubatum) is also found in Texas and is notorious for its highly abrasive, easily detachable seed heads.
A second group of Texas grasses often called foxtails belongs to the Setaria genus, including Yellow Foxtail (Setaria pumila) and Giant Foxtail (Setaria faberi). These species are common weeds in lawns and fields, recognized by their bushy, cylindrical seed heads. Although Setaria species are less dangerous than the Hordeum species, their bristles can still irritate skin and eyes.
Another group of problematic grasses includes the Cenchrus species, known as sandburs or buffelgrass. Sandburs, like the Longspine Sandbur, are hazardous because their seed heads are encased in hard burs covered with sharp spines and barbed bristles. Buffelgrass (Cenchrus ciliaris), though introduced for forage, also produces bristly seed clusters that can cause irritation and injury.
Regional Distribution Across the State
The prevalence of these problematic grasses varies significantly across the Texas landscape, though many thrive in disturbed soils and unmanaged areas. Little Barley (Hordeum pusillum) is exceptionally widespread, found across all ten ecological regions of Texas. It capitalizes on bare ground and is commonly seen along roadsides, in fields, and in heavily grazed rangelands.
Bristlegrass species, such as Southwestern Bristlegrass (Setaria scheelei), show a high abundance in Central Texas. This grass prefers the shade of open woodlands and the limestone canyons of the Edwards Plateau. Yellow Foxtail is common in urban and agricultural settings throughout much of Texas, often infesting lawns, pastures, and ditches.
The Trans-Pecos region and South Texas face a challenge with Buffelgrass, an invasive species that spreads aggressively along highways and into natural desert habitats. This grass forms dense stands and is a major concern in areas like Big Bend National Park. Its ability to colonize disturbed areas makes it a constant presence in roadside ditches and unmanaged fields throughout the southern half of the state.
Health Risks Associated with Foxtails
The danger posed by foxtail awns is due to their unique physical structure, which features microscopic, backward-pointing barbs. This design means the seed head operates like an arrowhead; it can only move deeper into soft tissue and cannot be dislodged by the body’s natural movements. Once the awn embeds itself, it carries environmental bacteria, often leading to severe infection and abscess formation.
The most common entry point is the space between the toes of animals, where the awn can penetrate the skin and cause painful swelling, limping, and persistent licking. If the awn enters the ear canal, it can cause an animal to shake its head violently or paw at the ear, leading to internal damage or a ruptured eardrum. In the nasal passage, a foxtail can cause sudden, intense sneezing fits or chronic nasal discharge.
In severe cases, the awns can migrate from the initial entry point, traveling through the body’s soft tissues. They can enter the chest cavity, causing pyothorax—an accumulation of pus in the space around the lungs. The awns can also reach vital organs or large blood vessels, creating widespread infection and deep abscesses that require surgical intervention.