thorny amaranth: erect annual of tropical central Asia and Africa having a pair of divergent spines at most leaf nodes
herb: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests
british west indies: the islands in the West Indies that were formerly under British control, including the Bahamas, Saint Lucia, Antigua, Grenada, Jamaica, Barbados, and Trinidad