calcium: a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals
metallic element: any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
katsura tree: rapidly growing deciduous tree of low mountainsides of China and Japan; grown as an ornamental for its dark blue-green candy-scented foliage that becomes yellow to scarlet in autumn