Common weeds in Puerto Rico and the U.S. Virgin Islands thrive in tropical and subtropical climates characterized by high temperatures, seasonal rainfall, and disturbed soils. Frequently encountered species include guinea grass (Megathyrsus maximus), which spreads aggressively in open fields and roadsides; Spanish needle (Bidens pilosa), a fast-growing weed common in gardens and agricultural areas; and purple nutsedge (Cyperus rotundus), considered one of the world’s most difficult weeds to control due to its underground tubers. Other widespread weeds include sensitive plant (Mimosa pudica), known for its rapid ground cover and thorny stems, and coatbuttons (Tridax procumbens), often found along highways and vacant land. These weeds compete with crops and native plants for nutrients, water, and sunlight, making effective management essential for agriculture, landscaping, and ecosystem conservation in both territories.
