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Stachytarpheta jamaicensis Is a species of plant in the Verbenaceae family. Native throughout the Caribbean, the species is commonly known as Blue porterweed or Jamaica vervain. It is pantropical, being found in the Indian Subcontinent, Southeastern Asia and West Tropical Africa, where it is known as Indian Snakeweed and Nettle-leaved vervain, formerly thought to be a separate species (Stachytarpheta indica). It is usually found along country roadsides and it grows also well as a ruderal plant on disturbed terrain. It is an invasive species in some places. (Wiki).