Urochloa reptans (sprawling signalgrass).

Urochloa reptans is an annual grass regarded as native to Asia, the Arabian Peninsula, Australia and the Pacific region, although its status is ambiguous in many countries. The species grows forming clumps of slender, creeping culms up to 50 cm tall that are capable of displacing other plants and grasses. It is considered an important weed in agricultural lands and pastures, but it can also invade disturbed sites, degraded forests, coastal areas, river and creek beds, and riparian forests. Currently, it is listed as invasive in Costa Rica, Puerto Rico, the United States Virgin Islands and some islands in Oceania, where it has been reported invading relatively undisturbed forests.