Allium giganteum, common name giant onion, is an Asian species of onion, native to central and southwestern Asia but cultivated in many countries as a flowering garden plant. It is the tallest ornamental Allium in common cultivation, growing to 1.5 metres (4.9 ft). In nature, the species is found in Iran, Afghanistan, Turkey, Turkmenistan, Tajikistan, and Uzbekistan. * Flower of A giganteum opening * Allium giganteum fully open