Although a species may be reported in many counties across the state, associated herbarium vouchers are often lacking. IPAW would like to help the Wisconsin State Herbarium collect voucher specimens for the species listed below. If a region/county is not specified, visit the Flora of Wisconsin database to see if a voucher specimen has already been collected in your county. Search the species name to view the map of collected vouchers for each species.
- Ailanthus altissima (tree-of-heaven)
- Amaranthus palmeri (Palmer amaranth)
- Anthriscus sylvestris (wild chervil)
- Carex spicata (spiked bracted sedge) – southeast counties
- Celastrus orbiculatus (invasive bittersweet)
- Corydalis incisa (Incised fumewort)
- Elaeagnus angustifolia (Russian olive)
- Elaeagnus umbellata (Autumn olive)
- Euonymus alatus (winged burning bush)
- Euonymus europaeus (European spindle tree)
- Ficaria verna (lesser celandine/fig buttercup) – southeast counties
- Galium verum (yellow bedstraw)
- Geranium robertianum (herb Robert) – any county except Door Co.
- Geranium sibiricum (Siberian cranesbill)
- Glyceria maxima (reed manna grass) – southeast counties
- Humulus japonicus (Japanese hop)- Door Co.
- Ligustrum spp. (Privets)
- Lonicera maackii (Amur honeysuckle)
- Miscanthus spp. (silvergrass) – naturalized specimens (not intentionally planted)
- Paulownia tomentosa (Princess tree)
- Phellodendron amurense (Amur corktree)
- Phytolacca acinosa (Indian pokeweed) – collect immature fruits, which are segmented. Native P. americana (American pokeweed) has full, unsegmented fruits.
- Pyrus calleryana (Callery pear)
- Ranunculus ficaria (lesser celandine or fig buttercup)
- Vincetoxicum nigrum (Black swallow-wort)
If any early-detection species are found, please also report to the DNR at invasive.species@wi.gov