Did you know that you can support the management and regulation of invasive plants in Indiana, just with your smartphone or computer? There are several invasive plants being assessed or reassessed by the Indiana Invasive Species Council to determine the threat they pose to Indiana. The more information they have, the more accurate their assessments are. For some species, we have very few reports of them escaping cultivation and invading, so every new report helps!
To report an invasive species, go to www.eddmaps.org/indiana, or use the GLEDN smartphone app. Be sure to include pictures so your report can be confirmed. (For instructions on how to report invasive species, go to https://www.entm.purdue.edu/iisc/index.html#gtco-report.
Here's what to look for in September!
Japanese stiltgrass (Microstegium vimineum)
An annual invasive grass, look for dense patches of this invasive starting to seed in forests, along edges, roads, and trails. The small oval shaped leaves are arranged alternately along the stem, and have a distinctive shiny/silver mid-rib. For more information on identifying stiltgrass, check out our youtube video at https://www.youtube.com/watch?v=y3lbumo0jjI&t=, or go to https://www.aces.edu/pubs/docs/A/ANR-1457/ANR-1457.pdf.
Mimosa (Albizia julibrissin)
Mimosa is a popular landscape tree known for its showy pink pom-pom like flowers. An invasive in the southern US, we are starting to see this tree escape cultivation in Indiana as well, particularly in the southern part of the state. While Mimosa is not currently listed as an invasive species in Indiana, it is being evaluated, and every new report helps.
This time of year, most adult mimosa trees are forming seed pods, which start out green and turn brown as they develop. Mimosa leaves are twice compound (or bipinately compound).
Sweet Autumn Clematis (Clematis ternifolia)
If you see vines covered in small white flowers, you could have the invasive Sweet Autumn Clematis, or Clematis terniflora. These vines were planted for their showy and fragrant flowers, but they area also aggressive and prolific seeders, creating a dense mat of vegetation as they grow over other plants blocking out sunlight.
To easily distinguish this invasive from our native Celmatis or Virgins Bower, just look at the leaves. If the edges of the leaves are smooth, it is invasive, the edges have teeth, it is native. http://www.mc-iris.org/native-or-invasive-clematis.html
Chinese yam (Dioscorea polystachya)
Chinese yam is an herbaceous vine that is spreading in Indiana. It has heart to fiddle shaped leaves, mostly opposite along the stem, with strong curving veins. You may also find aerial tubers along the stem. For help identifying this species, check out our ID video on youtube: https://www.youtube.com/watch?v=qg3NA4TWtn8
Chinese silvergrass (Miscanthus sinensis)
Chinese Silvergrass, also called Miscanthus, is a popular landscaping grass known for its dense clump forming nature and showy flower and seed heads. During September this plant is starting to flower in Indiana, making it easier to spot escaping yard planting and spreading on roadsides and natural areas.