Tree to 35–40 m, typically with a straight bole above a massively buttressed or bottle-shaped base. Bark grey brown, soon with deep but irregular fissures. Twigs red brown, puberulent when young, especially beneath; buds red, small, rounded, with even the terminal bud shorter than the width of the shoot. Leaves 8–11(–18) × 3–7 cm, base cuneate to rounded, apex acute, rarely acuminate, often with a tiny mucro; margin entire except for, usually, a few coarse teeth in the upper part; lower surface pale, glabrous or puberulent along veins, upper surface rather shiny, glabrous or sparsely hairy; petiole long (3–6 cm), usually glabrous. Peduncle of inflorescence 10–15 mm (elongating to 30 mm in fruit), glabrous; male inflorescence (1–)2–5-flowered, female or bisexual inflorescence 1 or 2-flowered. Staminate pedicels absent. Ovary densely hairy. Fruit black to blue or purple, glaucous, speckled with dots, oblong, large (24–27 mm), on a slender stalk; stone 15–20 mm, roughened and often with 8–10 deep longitudinal ridges. (Flora of North America 2021; Bean 1976).
Distribution United States Alabama, Arkansas, Florida, Georgia, Illinois, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, Texas, Virginia, Washington D.C.
Habitat In wooded swamps and river plains that are inundated except in summer; in pure stands or mixed with Taxodium distichum and Nyssa biflora.
USDA Hardiness Zone 6
Water Tupelo is a tree with a very specific natural habitat, often growing alongside the Swamp Cypress (Taxodium distichum) in forests that lie under as much as 2 m of water for much of the year; in these conditions, the lower trunk becomes massively flared and may grow to more than 4 m thick (American Forests 2020). Like other Nyssa this a very long-lived tree and is the usual source of ‘tupelo’ wood, which is strong and yellowish and used for flooring, veneers and wooden utensils (Exbury Garden 2021).
Like its more widespread and adaptable cousin N. sylvatica, the leaves turn yellow and scarlet in autumn, but, even in the gardens of its native United States, Nyssa aquatica seems to be a collectors’ tree. It is often assumed to be difficult to establish (though, in the wild, seedlings can only sprout when flood-waters recede) and to thrive only in swampy ground, unlike Swamp Cypress, which is a thoroughly adaptable plant. Jacobson (1996) cites historic records of trees to 38 m in habitat in South Carolina, and over 30 m in Virginia and Louisiana. In cultivation in northwest Europe, an additional issue is that Water Tupelo is a tree from low elevations in the southeastern states and can cope with winter cold but is adapted to long, hot and humid growing seasons.
Nyssa aquatica was in Peter Collinson’s collection at Peckham – now in south London – by 1735, from a collection made by John Bartram (Bean 1976), but there is a possibility of confusion with N. sylvatica in the various records of the species’s cultivation in the United Kingdom through the 19th century (Andrews 2001). More recent and reliable records include a specimen planted by Rollo and Ansell Hawkins at Cap Verde on Jersey, in a moist, sheltered valley in one of the warmest and sunniest places in the British Isles. In 2013 this was a dumpy-looking, poorly shaped but perfectly healthy tree, 9 m tall and with weeping lower branches. At Sheffield Park in East Sussex, by contrast, two plants sold as N. aquatica by Hilliers and planted in ordinary garden soil have grown very well so far, forming straight boles; the taller was 12 m by 2019 (Tree Register 2021). In the National Collection at Exbury in Hampshire, in a free-draining sandy soil, a young tree was 6 m in 2017 and already showed the robust matrix of exposed roots that is part of this tree’s adaptation to flooded ground (Exbury Garden 2021). At Lord Devonport’s arboretum at Peasmarsh Place in East Sussex, near a pond but in heavy clay, which hardens like concrete in a dry summer, one was 4 m tall after just 9 years in 2018 (Tree Register 2021); this is believed to derive from a collection made by Chris Reynolds and Dan Luscombe of Bedgebury National Pinetum. Other thriving young examples in southern England are at Higham Lodge in Suffolk, the Bodenham Arboretum in Worcestershire and, more surprisingly, the late Edward Needham’s garden in the cool maritime climate of western Cornwall (Tree Register 2021). The species is currently sold commercially in the United Kingdom by the Bluebell, Madrona and Starborough nurseries. There is remarkably little evidence for the tree’s successful cultivation elsewhere in the temperate world.