Too Much of a Good Thing
Driving through Lenoir County you might notice the bright fall foliage of the Chinese tallow tree (Sapium sebiferum). If you stop to watch the colorful leaves descend to the ground, you will see why the tree is commonly called the Popcorn tree. The unusual wax-coated seeds nestled at the ends of the branches are white and look like popcorn.
There is some evidence that Benjamin Franklin sent ‘a few’ seeds of the Chinese tallow tree to a colonist in Georgia in 1772. He refers to the plant as ‘most useful’. The Chinese tallow tree has been cultivated in China for 14 centuries as a seed crop and as an ornamental. The seeds are rich in lipids. The outer covering of the seeds contains solid fat (tallow) that were used in its native lands of China and Japan to make candles and soap. The seed kernels produce a drying oil called Stillingia oil used in machine oils, as a crude lamp oil and in making varnishes and paints, because of its quick-drying properties. This kernel oil was also used as a principle ingredient in China ink.
This tree was planted widely along banks of rice fields for erosion control in China and meal remaining from oil extraction was a primary fertilizer in rice paddies. The nectar from Chinese tallow tree is non-toxic, and has become a major honey plant for some beekeepers. The honey is of high quality and is produced copiously during the month of June, on the Gulf Coast.
In the early 1900s, the Foreign Plant Introduction Division of the U.S. Department of Agriculture promoted tallow tree planting in Gulf Coast states to establish a local soap industry. The plants have tremendous reproductive potential. A single, mature tree produces up to 100,000 seeds. Chinese tallow is very invasive. Chinese tallow tree is a rapidly growing tree that colonizes by root sprouts and seeds that are spread by wind, water and birds. The tree invades riverbanks and upland sites and is shade and flood tolerant. Once established, it is virtually impossible to eliminate by known methods and efforts to achieve effective control are being explored.
Besides altering the plant species composition, Chinese tallow woodlands have altered ecosystem processes. Their primary productivity is higher and ion concentrations in the soil have been changed.
It seems that in the southern U.S., Chinese tallow has become invasive like Kudzu, privet, mimosa, Japanese honeysuckle, chinaberry and wisteria. States including Florida, Louisiana, Mississippi and Texas have declared tallow trees a noxious weed. It has caused large-scale ecosystem modification throughout the southeastern U.S. by replacing native vegetation. It quickly becomes the dominant plant in disturbed vacant lots, abandoned agricultural land, natural wet prairies, and bottomland forests. Once established, Chinese tallow is virtually impossible to eliminate.
Although we enjoy the beauty and uniqueness of the Popcorn tree, this plant needs to be carefully managed. NCSU lists Chinese tallow tree as an invasive, exotic and suggests ways of controlling it: https://www.ncsu.edu/goingnative/howto/mapping/invexse/chineset.html.