Invasive Plants

Most plant species that are invasive here evolved on other continents, primarily Europe and Asia, or in some cases on the other side of this continent. They were brought here within the last five hundred years to be used for food, fuel, shelter, or medicine, or increasingly just for decoration. One reason that these alien or non-native plants become invasive is that the insects that evolved with the alien plants and were able to eat those plants, did not come with them. Most insects specialize in a small range of related species. Species from across the world are not likely to be similar enough for native insects to eat them. So alien plants have few insect predators. For similar reasons, there may be few other animals that will eat them. So, with few predators, many aliens that escape from cultivation have the advantage and invade the territory of native plants.

Often, it's more of a case of the aliens beating the natives back into areas disturbed by farming, mining, logging or other development. When these areas are allowed to return to "nature" they may soon become thickets of buckthorn, honeysuckle, privet, and multiflora rose, with few native plants able to survive. Diversity will be more likely to decrease as alien plants move in.

Besides the aesthetics and inconvenience to hikers and hunters, a more serious problem is the loss of native plants to support native animals, starting with the insects, and then with the birds and other animals that rely on the insects for food. Even if a bird can eat alien berries, it may not find any insects to feed its young. Even if an adult insect can get food from an alien plant, it may not be able to find a plant to support its offspring. Pollinators of certain native plants may disappear. Pollinators for agriculture my also disappear. Many birds may become scarce. Deer and rabbits may find our gardens more inviting than "natural" areas.

Just a few words for anyone wanting to make a connection between invasive plants and human immigration, segregation, or race relations. All people are the same species. We all originated from the same place. We've already invaded the rest of the world. Enough said about that.

The following invasive plants have been observed both in our own yard and at the nearby Skaneateles Conservation Area:

Acer platanoides (Norway Maple):



Alliaria petiolata (Garlic Mustard):




Berberis thunbergii (Japanese Barberry):


Elaeagnus umbellata (Autumn Olive):








Fallopia japonica (Japanese Knotweed):




Lonicera spp. (Exotic Bush Honeysuckles). This may include L. maackii, L. morrowii, L. tatarica, L. japonica, L. xylosteum, and their hybrids:




Rhamnus cathartica (Common Buckthorn or European Buckthorn):



Rosa multiflora (Multiflora Rose)


Multiflora rose (Rosa Multiflora) sprig.



Details of the image above showing hairs or comb-like fringes on leaf stems.


Both sides of a single compound leaf.