Amaranthus tricolor, known as edible amaranth, is a species in the genus Amaranthus (family Amaranthaceae). The ornamental plant is known as bireum in Korea; tampala, tandaljo, or tandalja bhaji in India; callaloo in the Caribbean; and Joseph's coat after the Biblical figure Joseph, who is said to have worn a coat of many colors. Although it is native to South America, many varieties of amaranth can be found across the world in a myriad of different climates due to it being a C4 carbon fixation plant, which allows it to convert carbon dioxide into biomass at a more efficient rate than other plants. Cultivars have striking yellow, red, and green foliage. Amaranthus gangeticus is considered a synonym of A. tricolor, but has been recognized as a separate species in the past. A. gangeticus is also known as elephant-head amaranth. It is an annual flowering plant with deep purple flowers. It can grow to 2–3 feet (0.61–0.91 m) tall. In Bangladesh, it has been used as a leafy vegetable. It may inhibit calcium retention in rice-based diets. The leaves and stems may be eaten as a salad vegetable. In Africa, it is usually cooked as a leafy vegetable. It is usually stir fried or steamed as a side dish in both China and Japan. In Korea, the plant is referred to as bireum (비름). Small-leaved, reddish-stalked chambireum (참비름, 'true bireum') is used as a namul vegetable in Korean cuisine. Considered a san-namul (wild green) that grows abundantly in the countryside, it tends to be foraged rather than planted and harvested. It has an earthy and nutty flavor, and goes well with both gochujang- and soup soy sauce-based seasonings, and bori-bap (barley rice). It appears on the coat of arms of Gonville and Caius College, Cambridge, where it is called 'flowers gentle'.