The viridian metaltail (Metallura williami) takes its name from the Latin viridis, meaning green – viridian means a bluish-green colour. It is found in Colombia and Ecuador, is often aggressive, and males are particularly territorial around flowers. Similar in appearance to the Tyrian Metaltail (Metallura tryianthina), only the Viridian has a purple tail. The male Viridian Metaltail is mostly an iridescent green with some rusty markings below his eyes, his wings and rump. The upper tail feathers have a bluish-purplish tint. The female has some rusty speckling on her underparts.