The ERA Tool is a map-based, searchable application to select native plants for restoration and pollinator habitat enhancement by US Environmental Protection Agency (EPA) Level III Ecoregions. Since ecoregions are areas of similar climate and topography that contain characteristic, geographically distinct assemblages of natural communities and species, they are an ideal organizing unit for selecting plants for restoration. State floras, on the other hand, have many species that only occur in some ecoregions and are not appropriate choices for restoration elsewhere.

Jump To Menu

The left-hand Jump to menu includes a drop-down menu of US states. Select a state to auto-zoom the map to that state.

Legends & Layers Menu

The left-hand Legends & Layers menu includes a Seed Zones data layer that can be toggled on/off; default display is ‘off’.

Map Display

The Google base map includes standard pan and zoom functions, and interactive ‘hot spots’. The left-hand functional menus use show/hide display and may be opened/closed by selecting the double-arrow icon. US EPA ecoregions are outlined, and may be individually selected to display a pop-up window containing a short list of Workhorse Species for that location.

The Workhorse Species pop-up window contains a short list of plants, shrubs, grasses and forbs. In the upper-right corner of the window, select the white arrow to advance the display through the plant subset and the ‘x’ to close the window. In the bottom-right corner of the window, select View All Plants to display all plants species for the location in tabular format at the bottom of the browser window and Download to generate a Microsoft Excel file of the workhorse species.

Workhorse plants, as defined for the ERA Tool, are native plants within a specific ecoregion that are known by design and horticulture professionals to be hardy, durable, consistent, tolerant of a wide range of environmental conditions, commercially-available, traditionally used for slope erosion control, exposed sites, roadside revegetation, and are widely distributed throughout the ecoregion. Revegetation plants are also extremely useful for revegetation and restoration but are less widely used than workhorse plants. Pollinator plants provide significant pollinator benefits. Therefore the ERA Workhorse/Pollinator plants will generally be the most useful for creating pollinator habitat, followed by Revegetation/Pollinator plants. Other plants in the database are useful native plants with varying degrees of known utility, commercial availability, and pollinator benefits; all of them potentially have something to offer the restoration specialist.

Tabular Data Display

A comprehensive data set of native plant species can be viewed in tabular format. Select the arrow icon at the center bottom of the display window to display the table at half-size. Select the arrow icons at the top of the table display to enlarge data table to full screen or ‘hide’ data table.

The data table includes a ‘tab’ for each US ecoregion in numerical order. The highlighted tab represents the US ecoregion data displayed in the table and displays the ecoregion name in bold face type. Toggle individual tabs to refresh table display.

Toggle data table column headings to resort data in ascending/descending order.

Select the search filter icon to the right of column headings (not available for all columns) to generate a drop-down menu with filter criteria; select one or more check boxes and the ‘Filter’ link to generate a subset of data. One or more search filters can be used to refine data sets. The number of species matching selected criteria is displayed in the lower-right corner of the table display. The filter selections remain applied to subsequent plant searches until singularly toggled off or the Clear Filters function is selected.

Below the row of ecoregion tabs are links to zoom the map to the selected ecoregion, download data sets, and clear search filters.

Data Considerations

The plants that occur in each ecoregion were determined by intersecting USDA PLANTS county distribution data with EPA Level III Ecoregions. This means that if counties or ecoregions are large then plants may occur in only part of the designated ecoregion. Furthermore, plant distribution data contain errors of both omission and commission, that is, states and counties where plants actually occur are not included in the USDA PLANTS distribution data, and plants are attributed to states and counties (and thus ecoregions) where they do not occur. We recommend you use the best plant distribution data sources available to be sure selected plants are native to your project sites; online state atlases are usually highly informative.

Native Status is a key data field since it indicates which native plants have spread beyond their original North American ranges. If Native Status = NI (native and introduced), it is extremely important to consider other data sources and determine if the plant is native to your part of the world. These NI plants were retained in the data because they are so useful within their native ranges, e.g. Helianthus annuus (sunflower) or Robinia pseudoacacia (black locust), but many of them are nuisance plants or worse outside their native ranges. Furthermore, in the Native Status field as in all fields in large databases there are mistakes—plant distributions continue to change and now faster than ever—so some plants labeled L48 (N) may have indeed spread beyond their native ranges.

All the foregoing points strongly suggest a careful review the ERA results using local knowledge and other resources because:

• Some of the plants may not occur in your area
• Some of the plants may be weedy in your area
• Some of the plants may occur only in very specialized habitats in your area

Currently the best single place to check the native and introduced portions of North American plants is the Biota of North America Program (BONAP). It too has errors so continue to use your best informed judgement about the plants to include in your projects.

The USDA PLANTS Database provides the nomenclatural and distributional standard for this project, including plant names, distributions, and much ecological data. See Data Sources for more information. Additional notes for a few of the data fields follow:

• Native Status: See https://plants.usda.gov/about_adv_search.html for more information and field values.
• Height (feet): Given as a range or a single value, in which case that value represents typical individuals not maxima or minima.
• Commercially Available: From USDA PLANTS and The University of Chicago.
• Pollinator Value: Calculated from the individual pollinator fields.

Additional Links

ERA Tool includes supporting resource links in the upper-right top of display.

• The Technical Report links to an online, interactive version of 500+ page comprehensive report, Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat, with a pdf download.
• The Native Revegetation Resource Library is a comprehensive database-driven tool containing hundreds of reference materials (reports), organized by report type, restoration type, topics, and publication date.
• Use the Kramer Lab: Vendor List link to find native plant sources for the species in the tool.
• Downloads of all ERA plant species data sets and user-generated subsets are available in Microsoft Excel format.
• A list of Data Sources used to generate the ERA Tool includes short descriptions of each.