The link categories above point to a representative list of species that are, or have potential to be, invasive in Maryland. It is by no means an exhaustive list, but includes species of great concern to the Maryland Invasive Species Council (MISC).
MISC’s Criteria for Selecting Invasive Species
These lists include harmful non-native species of concern because they fit one or more of the following criteria:
- Currently regulated by the state of Maryland or a local jurisdiction within Maryland
- Currently regulated by federal law and present in Maryland
- Widely recognized by biologists and resource managers to degrade natural ecosystems, or negatively affect native species
- Known to have significant economic impacts on agricultural ecosystems, public infrastructure or natural resources, including impact on recreational activities
- Causing or having the potential to cause deleterious effects on human health.
MISC is highlighting only certain species. In fact, invasive species lists cannot be all-inclusive because of the evolving nature of the invasive species problem, and because expert opinions can differ about the harm caused by introduced species. Moreover, the MISC list is expected to change over time as new invasives are discovered. Note that the MISC list does not come from original research, but is a curated compilation of species listed by other sources. Do not depend on this list as the sole source for information on invasive species in Maryland.
MISC’s Purpose for Listing Invasive Species
This list is designed as a guidance tool for:
- On-the-ground routine management of existing invasive species
- Identification and prioritization of emerging or established invasive species that require urgent action to control
- Design, installation, and maintenance of landscaping
- Regulatory prevention, quarantine, and enforcement activities by local, state, and federal agencies
- Support of funding requests to the legislature, government agencies, and private organizations
- Education of legislators, regulators, commercial plant and animal industries, non-profit and government environmental organizations, and the public
The list does not have regulatory or legal status, and is expected to change over time as the process of invasive species identification and management continues.
Species and Cultivars
The position of MISC is that cultivars of invasive species are presumed to be invasive unless scientifically documented otherwise. Plant specialists have selected or developed cultivars and hybrids of many invasive species. Sellers may be labeling the resulting horticultural varieties as non-invasive (e.g., cultivars of daylily, Hemerocallis hybrids); however, some cultivars originally specified as sterile or non-invasive (e.g., ‘Bradford Pear’ Pyrus calleryana) have become significantly invasive. Generally, it is advisable to treat cultivars and hybrids of invasive plants as invasive unless proven otherwise.
Commercial Availability of Invasive Plants
Some plant species listed as invasive are of commercial importance to the nursery industry and are routinely sold and planted in our region. Moreover, the various invasive lists are continually adding new plant species. MISC encourages nurseries, landscape architects, designers and installers, and the gardening public to consider alternatives to invasive species, particularly when plantings are done near parks and other natural areas.