Ageratina popayanensis
Native only to Colombia, this shrub or small tree grows in the Andes and can reach about 10 to 16 feet tall. Terminal, flat-topped clusters contain numerous small white to yellowish flowers. In Colombia, it occurs in humid mountain forests and related habitats from about 3,300 to 12,100 feet. In eastern Antioquia, branches have traditionally been tied together as a brush to remove scum during sugarcane processing. Photographed in Colombia.