Bermuda grass (Cynodon dactylon) is a perennial turf and forage species found globally in warm climates. Although widely used for lawns and pasture, it is also classified as one of the world’s most aggressive invasive weeds due to its rapid growth. The common name is misleading, as the plant is not native to Bermuda, where it is an introduced species. This highly adaptable grass originated in the Old World, tracing its evolutionary roots back to the African continent and Eurasia.
The True Geographic Roots
The native habitat of Cynodon dactylon is thought to be tropical Africa, particularly East Africa and the Nile Valley region. The greatest concentration of species within the Cynodon genus is still found in Africa, pointing to this continent as the center of its evolutionary origin. From this starting point, the grass spread naturally across what is known as the Old World, establishing itself long before human-aided transport became common.
This ancient species became widespread across Southern Europe, the Middle East, and large parts of India and Southeast Asia. In India, the grass has a history so deep it is mentioned in the Veda, the sacred Hindu writings, where it is referred to as the “Shield of India” for its importance as livestock forage. Its natural presence across this vast Afro-Eurasian range distinguishes it as an ancient, established inhabitant of these regions.
How Bermuda Grass Got Its Name
Despite its Old World origins, the grass acquired its common name from a geographic mix-up that occurred during its journey to the Americas. It was likely transported across the Atlantic during the era of colonization and global trade, often accidentally in contaminated hay or soil, or intentionally as a resilient forage crop. The grass was introduced to the United States around the mid-1700s, with a reported introduction into Savannah, Georgia, in 1751.
The island of Bermuda served as a prominent stopover point or an early, highly visible location where the grass established itself in the New World. Because of its noticeable presence in Bermuda, early American colonists and botanists mistakenly assumed the island was its origin, thus permanently linking its name to the archipelago. The name “Bermuda grass” therefore reflects a geographical waypoint on its transcontinental journey rather than its true native home.
Factors Driving Global Establishment
The success of Bermuda grass in colonizing new regions is due to a combination of biological and ecological adaptations. It is a warm-season perennial grass, meaning it thrives in hot temperatures and has a long lifespan, allowing it to survive through multiple growing seasons. The plant’s aggressive nature is rooted in its ability to spread rapidly using two specialized stem structures.
The first type of stem is the rhizome, which are underground horizontal stems that aggressively grow beneath the soil surface. These rhizomes allow the plant to survive drought by entering a period of dormancy, and they store energy reserves that facilitate quick re-sprouting after disturbance or fire. The rhizomes of Bermuda grass are typically concentrated in the top six inches of soil but can penetrate down to over a foot in depth.
The second structure is the stolon, which are above-ground runners that creep along the soil surface, rooting down at the nodes. This allows the grass to form dense, interconnected mats, quickly covering and dominating an area. A single shoot from a rhizome can cover over 25 square feet of soil surface in just five months. This dual-stem approach, utilizing both subterranean and surface runners, makes it extremely difficult to eradicate once established.
In addition to its growth mechanisms, the grass possesses a high tolerance for environmental stressors, aiding its global spread. It can tolerate a wide range of soil types and is highly resistant to both heat and drought conditions. Furthermore, it is a C4 grass, a photosynthetic pathway that is highly efficient in hot, sunny, and dry environments. This efficiency gives it a competitive advantage over many native species in tropical and subtropical regions.