Axonopus is a genus of approximately 78–107 species of grasses in the family Poaceae (order Poales), commonly known as carpet grasses. The genus was described by the French botanist Ambroise Marie François Joseph Palisot de Beauvois in his Essai d’une Nouvelle Agrostographie in 1812. The name is widely used in both tropical horticulture and ecological literature for the low-growing, mat-forming species that typify the group.
The genus is distributed primarily throughout the tropical and subtropical Americas, ranging from the southern United States through Central America, the Caribbean, and into South America as far as Argentina. One species is native to tropical Africa and one occurs on Easter Island, giving the genus a predominantly Neotropical but broadly pan-tropical distribution. Several species have been introduced beyond their native ranges — notably to South and Southeast Asia (including India and Bangladesh) and to the Pacific.
Plants are typically perennial, often stoloniferous or rhizomatous, and form dense, low mats of vegetation. Many species display a notable tolerance for periodic flooding and waterlogging, making them characteristic components of seasonally wet savannas, grasslands, and disturbed ground in lowland tropical regions. The most widely cultivated members, Axonopus compressus (tropical carpetgrass) and Axonopus fissifolius (common carpetgrass), are used as lawn and pasture grasses across tropical and warm-temperate regions of the world.
Etymology
The genus name Axonopus was coined by Palisot de Beauvois in 1812. It derives from the Greek axon (axle or axis) and pous (foot), likely referring to the arrangement of the spikelets along the rachis branches of the inflorescence, which radiate from a central axis. Synonyms previously applied include Lappagopsis Steud. and Cabrera Lag.
Distribution
Axonopus is native primarily to tropical and subtropical regions of the Americas, from the southeastern United States (Alabama, Arkansas) south through Central America, the Caribbean (including the Bahamas), and South America (Colombia, Argentina, and elsewhere). One species occurs in tropical Africa (Angola) and one on Easter Island. Several species have been introduced to Asia (India, Bangladesh, Andaman Islands) and the wider Pacific, where some have become naturalized.
Ecology
Many species are adapted to seasonally wet or poorly drained soils and can tolerate periodic submersion, making them common in tropical lowland savannas, roadsides, and disturbed grasslands. The stoloniferous or rhizomatous growth habit allows them to form dense ground cover that suppresses competing vegetation. Axonopus compressus and A. fissifolius in particular are associated with moist, nutrient-poor soils in disturbed or managed landscapes across the tropics.
Cultivation
Several Axonopus species — most notably Axonopus compressus (tropical carpetgrass) and Axonopus fissifolius (common carpetgrass) — are cultivated as warm-season lawn grasses and pasture species in tropical and subtropical regions worldwide. They are valued for their low growth habit, tolerance of shade and moisture, and ability to form a dense, weed-suppressing mat with minimal maintenance. They are widely used in lawns, playing fields, and forage systems across Southeast Asia, the Pacific Islands, and parts of Africa and the Americas.
