Sand spurs belong to the grass genus Cenchrus. These annual or sometimes perennial plants are notorious across warm regions for their painful reproductive structures, often referred to as sandburs or burrgrass. They produce small, hard seed pods densely covered in rigid spines. Understanding the specific visual and physical traits of the entire plant allows for better identification and avoidance, especially during the warm months when the spiny seeds begin to mature.
Identifying Characteristics of the Mature Plant
The sand spur plant is a type of warm-season grass that often goes unnoticed until its seed pods appear. It typically exhibits a low-growing, sprawling, or mat-forming habit, though some varieties can grow upright to heights of over two feet. The stems, or culms, are generally round and smooth, sometimes showing a distinct reddish or purplish tint near the base. The leaf blades are flat, narrow, and often a pale or light green color, resembling many common turf grasses. The surface of the leaves can feel rough to the touch, and they may be rolled or folded in the shoot.
Detailed Anatomy of the Sand Spur Burr
The burr is the mature seed pod, developing along a spike-like terminal axis on the stem. When young, the burrs are small, green, and relatively soft, but they quickly harden and change color as they mature. A fully developed burr is oval to spherical, typically measuring between 0.2 and 0.4 inches long, roughly the size of a small pea. The most defining feature is the dense covering of rigid spines that radiate outward from the seed pod’s center. These spines are equipped with microscopic, backward-facing barbs near the tip, which allow the burr to cling tenaciously to skin, clothing, and animal fur for dispersal.
Typical Growing Environments
Sand spurs thrive in environments characterized by specific soil and climate conditions across warm climates. The grass has a strong preference for sandy soils that are dry and low in nutrient content, which is why it is common in coastal areas, including dunes and sandy beaches. The plant is highly adaptable and takes advantage of open ground where competition is sparse. Sand spurs are frequently found in disturbed areas, such as poorly maintained lawns, abandoned fields, roadsides, and construction sites.