Description and habitat
Black Tupelo or Black Gum (Nyssa sylvatica) is among the most unique species in the Long Point Basin. Historically included as part of the Dogwood Family (Cornaceae), it is now assigned to it’s own family, Nyssaceae, which is sister to another group containing the Hydrangeas. There are around 7-10 species of Tupelo globally, most are native to North America, including the Swamp Tupelo (Nyssa biflora) and Water Tupelo (Nyssa aquatica), keystone species of swamps in the southern United States. In ideal conditions, Black Tupelo is a tall deciduous tree that can attain a longevity of 500 years or more.
Black Tupelo bears alternate, simple leaves with smooth margins, each measuring 5-12 cm – small for a deciduous tree. These leaves are a deep, shiny green in the summer months. In the autumn, Black Tupelo leaves transform into a brilliant red. These trees tend to defoliate (lose their leaves) before other hardwood species, usually in early to mid October. The bark on mature trees, a defining identification characteristic of this species, has deep burrows and blocky ridges, almost like alligator-bark. The flowers, which are light-green and minute, are located at the top of a long stalk. Tupelos are dioecious, with male (pollen) and female (fruit). The fruits, which are black-blue oval 1cm long drupes, ripen in September.
In Canada, Black Tupelo is most readily encountered in Norfolk County, Elgin, and southwest Middlesex (in the Skunk’s Misery area). Black Tupelo is distributed from southwestern Ontario to central Florida west to Texas. Although it is a woodland tree in the more southerly areas of it’s range, Black Tupelo is almost always found in swamps within it’s Canadian distribution. In these habitats, it is most readily found alongside Red Maple (Acer rubrum), Black Ash (Fraxinus nigra), Green Ash (Fraxinus pennsylvanica), White Elm (Ulmus americana), and Silver Maple (Acer saccharinum). Although it can tolerate varying substrates, Black Tupelo has a strong preference for acidic soils – a pH of 5.5-6.5 is ideal, while it is intolerant of alkaline areas. Tupelos, although a brilliant shade-tree with consistently beautiful autun foliage, is not widely utilized in horticulture due to these unique growing requirements. However, it can be utilized more widely where it’s soil preferences are met.
Wildlife importance
Songbirds (Passeriformes) and other birds readily feed on the fruits of Black Tupelo, which are an important autumn food source. Tupelo leaves are also an important food source for many lepidopterans (butterflies and moths). These include the Tupelo Leafminer Moth (Antispila nysaefoliella), False Underwing Moth (Allotria elonympha), Azalea Sphinx Moth (Darapsa pholus), Cadbury’s Lichen Moth (Comachara cadburyi), and Hebrew Moth (Polygrammate hebraeicum)
Fun facts
- Despite common names like Black Gum or Sour Gum, the Black Tupelo tree does not produce any significant resin.
- Similarly to Basswood (Tilia americana), Black Gum is prized as an important source of nectar for honey production
- Discovered by fossilized evidence, tupelos existed in North America and even Europe tens of millions of years ago, during the Eocene and Miocene epochs
- Black Tupelo is shade tolerant and has a unique branching structure, consisting of layers of branches extending laterally from the main trunk
Written by Matthew Palarchio, HBSc in Environmental Sciences, Western University.
Photo Credits (L-R) – © Matthew Palarchio (tree form), © Matthew Palarchio (bark), © Matthew Palarchio (summer leaves), Stock Photo retrieved from Canva (autumn foliage)
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