Amur honeysuckle (Lonicera maackii, Caprifoliaceae) is one of several bush honeysuckles introduced to the United States. It’s distinguished from related plants by its acuminate (sharply-pointed) leaves, hollow piths (stem centers), and paired, round red fruit that grow on very short peduncles (stems). It also fruits much later than other honeysuckles (October-November).
This large shrub/small tree was first introduced from east Asia in the late 1890s, and it was later promoted for use in gardens and hedgerows. The fruit proved to be attractive to birds and mammals who helped disperse the seeds in their droppings. Over time it has spread aggressively in the wild and has become a serious invasive that outcompetes native plant species. It grows rapidly, tends to form dense arching thickets, leafs out early, and holds its leaves well into autumn. These features work to limit the sunlight available to natives.
Amur honeysuckle also competes with native plants for water, nutrients, and pollinators, and may release phytotoxic chemicals that inhibit their growth. Within a few years of introduction it can establish a monoculture that excludes all other plants in the area. Since animals often rely on the food provided by native plants, such disruptions can have a deleterious effect on food webs. For these reasons several states have banned the sale of Amur honeysuckle or work to control it.