Boston Harbor Islands National Recreation AreaPage 10 of 104
Black Gum (Nyssa sylvatica)
About Black Gum (Nyssa sylvatica)
Black gum, also known as black tupelo, is a deciduous tree native to eastern North America and parts of Mexico. A member of the Nyssaceae family, it is remarkably adaptable and can grow in a wide variety of habitats, from upland forests and rocky slopes to swamps and stream edges. Although it tolerates many conditions, black gum grows best in moist, acidic soils.
The species is known for its strong root system, which helps anchor trees in wet soils and contributes to erosion control along wetlands adjacent to rivers and streams. This adaptability has made black gum an important component of many natural ecosystems throughout its range.
Black gum is best known for its exceptional fall color. In autumn, its glossy-green leaves transform into brilliant shades of scarlet, crimson, orange, and purple, creating one of the most striking seasonal displays in northeastern forests. Individual trees often begin coloring earlier than surrounding species, making them easy to spot in the landscape.
The small greenish-white flowers provide an important nectar source for bees and other pollinators. Female trees produce dark blue-black fruits that are consumed by a variety of birds and mammals, making black gum an important source of food for wildlife throughout the year.
The name “tupelo” comes from the Creek language, meaning “swamp tree,” reflecting the species’ association with wet habitats in parts of its range. Indigenous peoples used the strong wood for tools, bows, and baskets, while various parts of the tree were used for medicinal purposes and natural dyes.
Identification
Black gum is a medium to large tree with a straight trunk and narrow pyramidal crown (a cone-like shape, wider at the base and tapering upward to a single apex) when young. As it matures, the crown becomes broader and more irregular.
The leaves are simple, alternate, and typically three to six inches long. They are widest near the middle, giving them an oval or elliptical shape, and taper toward both the base and tip. The upper surface is glossy dark green during the growing season, while the leaf margins are smooth or only slightly toothed.
The bark is one of the tree’s most distinctive features. On mature trees, it becomes dark gray and deeply furrowed, often resembling blocks or squares that resemble alligator skin.
In late spring, clusters of small greenish-white flowers emerge among the leaves. Female trees later develop oval fruits that transition from green to dark blue-black as they ripen. In autumn, the tree is especially easy to identify with its vivid red foliage, which is among the brightest of any native northeastern tree.
Phenology Highlights
Phenology is the study of recurring seasonal events in plants and animals. The following phenophases, distinct and observable stages in the annual life cycle of a plant or animal, are monitored as part of the National Parks of Boston Tree Monitoring Program.
Breaking Leaf Buds

Environmental Studies, Lake Forest College.
As temperatures warm in spring, black gum buds swell and open to reveal light green leaves. New leaves emerge soft and delicate before gradually developing their characteristic glossy appearance.
Leaves & Early Season Leaf Expansion
Black gum leaves expand steadily through spring, forming a dense canopy of glossy green foliage. The leaves are simple, alternately arranged, and widest near the middle before tapering toward both ends. Mature leaves typically measure three to six inches long and have smooth or nearly smooth margins.
Colored Leaves & Falling Leaves
Leaves often turn shades of scarlet, crimson, orange, and purple, sometimes displaying multiple colors on the same tree.
Flowers or Flower Buds & Open Flowers with Pollen Release
In late spring, small clusters of greenish-white flowers appear among the leaves. Black gum trees are polygamo-dioecious, meaning individual trees may bear male flowers, female flowers, or perfect (bisexual) flowers, with some trees producing a combination of these flower types. Female flowers appear individually or in small groups on long stalks emerging from the leaf axils, while male flowers occur in greenish-white spherical clusters. Perfect flowers contain both male and female reproductive parts within the same flower.
Black gum flowers are an important nectar source for bees and other pollinators. Male flowers produce pollen that is transferred by insects visiting the nectar-rich blossoms.
Fruits
Following successful pollination, female and perfect flowers develop into small fleshy fruits. The fruits are oval-shaped and green at first, gradually enlarging throughout the summer.
Ripe Fruits & Recent Fruit or Seed Drop
By late summer and early autumn, fruits ripen to a dark blue or black color. The fruits are highly valued by birds and other wildlife, which often consume them soon after they mature. As fruit ripen, they may fall beneath the tree before being removed by wildlife.
Learn More
- Amwoga Khalwale. (2024, July 18). Black Tupelo Tree: History, Leaves, Flowers, Bark (Pictures) – Identification Guide. American Gardener.
- Nyssa sylvatica - Plant Finder. (n.d.). Missouri Botanical Garden. Retrieved September 4, 2026.
- Nyssa sylvatica (black-gum, black tupelo): Go Botany. (2025). Native Plant Trust.
National Parks of Boston Tree Monitoring Program
By observing seasonal changes in trees, volunteers help scientists better understand how plants respond to changing environmental conditions over time.
Where this belongs
- Boston Harbor Islands National Recreation Area
- Boston National Historical Park
Where this page came from
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