By Liz Kimbrough Palm trees are iconic figures in tropical landscapes, providing food, tools, medicine and materials for homes to millions globally and playing key roles in many ecosystems. Now, researchers have determined that more than half of global palm species could be at risk of extinction. Using novel machine-learning techniques and data from the IUCN Red List of Threatened Species, researchers from the Royal Botanic Gardens, Kew, the University of Zurich, and the University of Amsterdam investigated the extinction risk of nearly two-thirds of the palm family. Of the 1,889 species of pa…