The Blue Porterweed (Stachytarpheta jamaicensis) is a perennial herbaceous plant of the tropics and a weed of coastal coconut plantations. It can reach 6ft (1.8m) high before its stems collapse. Its blue flowers, about 0.25in (0.6cm) in diameter, are terminated by long stringy tips. Their sweet nectar attracts a wide variety of butterflies. Its leaves are used as purgative and sedative herbal tea.