Any of about seven species of trees that make up the genus Nyssa in the sour gum family (Nyssaceae).
Five are found in moist or swampy areas of eastern North America, one in eastern Asia, and one in western Malaysia. They all have horizontal or hanging branches, broad leaves, and male and female flowers on different plants. North American species bear greenish-white flowers and small bluish-black or purple berries. The most widespread North American species is the black gum . Tupelo wood, most of which comes from the water tupelo ( N. aquatica ), is pale yellow to light brown, fine-textured, and strong. It is used for crates and boxes, flooring, wooden utensils, and veneers.