A taxonomic key for identifying seeds of undesirable landscape plants

The seeds of invasive plants and noxious weeds are commonly found in topsoils used for landscaping. Their presence leads to significant costs associated with weed control following germination. Images and in-depth descriptions for relatively few weed seeds are presently available in a single source. As seeds move from state to state and across international borders, it is increasingly important to be able to identify the seeds of undesirable plants. This is especially the case for species restricted by government regulations. The primary objective of this research was to develop a taxonomic key that will assist with identification of undesirable weed seeds (i.e., indicated as invasive or noxious by state or federal governments in the United States) and seeds that are presently considered invasive. We obtained our seed sample library of over 1100 species directly through field collection as well as donations from collaborators around the world. Seeds of each species were photographed using stacking photomicrography techniques, measured, and described using 14 characteristics. Of these, the primary basis for describing the seeds and keying them were seed shape, length, length to width ratio, seed surface characteristics and seed color. Future efforts will include hosting the key on a web platform, in order to function as an interactive tool. The primary advantage of this approach is the ability to progressively narrow potential seed candidates based on any feature that can be accurately identified.