Water tupelo (Nyssa aquatica): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Nyssa aquatica L. in USDA PLANTS, dogwood family
Other names	Cottongum, sourgum, swamp tupelo, tupelo-gum and water-gum (Silvics)
Native status, USDA PLANTS	Native in the lower 48 states
Form, Silvics	A large, long-lived tree with a swollen base that tapers to a long, clear bole; it often occurs in pure stands
Size, Silvics	On a good South Carolina site, 30-year-old trees averaged about 23 m (75 ft) tall and 33 cm (13 in) in diameter; trees grown 50 to 75 years on a good site with plenty of sunlight may reach 51 to 66 cm (20 to 26 in) in diameter above the butt swell
Shade, Silvics	Classed as intolerant of shade; it survives codominant but not overtopping competition
Roots, Silvics	A shallow root system in saturated soils, with adaptations for flooding that include adventitious water roots just below the water line
Green weight of the wood, NRS-38	56 lb per cubic foot, without bark

Native range and sites

The Silvics of North America handbook (Agriculture Handbook 654, volume 2, 1990) says water tupelo grows throughout the Coastal Plain from southeastern Virginia to southern Georgia, and from northwestern Florida along the Gulf of Mexico to southeastern Texas, extending up the Mississippi River Valley as far north as the southern tip of Illinois. It describes the tree as growing in southern swamps and flood plains where its roots are periodically under water, in low wet flats, sloughs and deep swamps. On some sites the handbook says water may reach a depth of 6 m (20 ft) in rainy seasons and stay as high as 4 m (13 ft) for long periods. Soils range from mucks and clays to silts and sands, and are mostly moderately to strongly acidic.

The handbook names water tupelo as a major component of two forest cover types, Water Tupelo-Swamp Tupelo and Baldcypress-Tupelo. In stands with baldcypress, it says baldcypress is usually predominant, and in sloughs and moving water water tupelo usually occupies the deeper parts.

Flowers, fruit and seed

Silvics says water tupelo is polygamo-dioecious, with minute greenish-white flowers that appear before or with the leaves in March or April and are pollinated by wind and probably bees. The fruit is an oblong drupe about 1 to 4 cm (0.5 to 1.5 in) long that is dark purple with conspicuous pale dots when mature, from September through December of the first year, and contains a bony, ribbed, one-seeded stone. Seeds are dispersed mainly by water and the fruit floats as long as the outer skin is intact; the handbook says seeds do not germinate until the water recedes, which may be midway to late in the growing season. Forest trees begin seed production at about 30 years or about 20 cm (8 in) in diameter.

Growth

The handbook says growing-season flooding just short of continuous may give near-optimum soil moisture for growth, and that any drastic change in normal water levels can decrease growth. It notes that age is hard to determine because the species is known to have false rings. Ten-year diameter growth for trees free to grow in unmanaged stands on an average site is given as about 8 cm (3 in), and pure unmanaged second-growth stands with a basal area between 57 and 69 square m per hectare (250 and 300 square feet per acre) are called not uncommon.

Planting and wildlife

Silvics says water tupelo is one of the few species able to survive extended periods of inundation, so it is favored for planting in very wet microsites, around buildings and in parks. Wood ducks, other birds, squirrels, raccoons and deer eat the fruit, deer feed on foliage, twigs and stump sprouts, and the flowers have some value as a source of tupelo honey.

Wood

Silvics says water tupelo wood has a fine, uniform texture and interlocked grain, and that dried properly the lumber is used for boxes, pallets, crates, baskets and furniture. It says buttresses of trees growing in flooded areas hold wood much lighter than the upper portions of the same trees, and that the butt portion is probably best suited to pulping products. The Wood Handbook (FPL-GTR-282, 2021) groups water tupelo with black, swamp and Ogeechee tupelo as wood that is quite similar in appearance and properties, moderately heavy and moderately strong, and says interlocked grain means tupelo lumber requires care in drying. The same wood group is on the black tupelo page. Table 5-3b has a separate water tupelo row, shown below.

Wood Handbook Table 5-3b	Specific gravity	Modulus of rupture (lbf per square inch)	Side hardness (lbf)
Green	0.46	7,300	710
At 12% moisture content	0.50	9,600	880

The Wood Handbook states that specific gravity is based on oven-dry weight and the volume when green or at 12% moisture content. The green weight of the wood without bark is in the NRS-38 table, the same figure used in the log weight calculator.

Diseases, insects and damage the handbook names

Silvics (1990) names these agents.

Fire. Called a major enemy: it scorches the thin bark, which the handbook says allows entrance of rot-causing fungi.
Forest tent caterpillar. Malacosoma disstria is called a serious enemy in some years and locations; the handbook says more than 202,350 hectares (500,000 acres) along the Gulf Coast from Louisiana through Alabama were defoliated in a single year. Trees defoliated annually seldom die but may add 30 percent or less of the annual diameter growth of unattacked trees.
Leaf disease. Mycosphaerella nyssaecola has caused premature defoliation, but the handbook calls the impact negligible.
Flooding. The tree is described as one that survives extended inundation; the guide on flooding injury to trees covers flooding in general.

The guide on reporting a pest in the United States and the Canada reporting page give the offices that take sightings of regulated pests. Who may apply pesticides is in pesticide licences by country.