Issue 8, June 23, 2014

Illinois Invasive Plant Phenology Report

Several invasive plant experts from around the state have started a new series of reports focusing on the phenology of invasive plants in Illinois. The intent of these reports is to provide an update on the development of invasive plants across the state of Illinois -- what plants are in bloom, leafing out, setting seed, or senescing in different areas of the state.

Readers are encouraged to share what they see in their area of the state by emailing Chris Evans, Invasive Species Campaign Coordinator of the Illinois Wildlife Action Plan (

Phenology Report for May 16, 2014
(Contributors include Cathy McGlynn, Karla Gage, Marilyn Leger, Eric Smith, Mike Davis, Matt Baulk, Paul Bane, David Crady, and Mike Daab)

Southern Illinois

  • Garlic mustard, Alliaria petiolata - Second-year plants are senescing, becoming chlorotic; siliques have matured and seeds are hardening. Seeds have not yet begun to dehisce as of June 3. Once this occurs, contact with the plant is not advised because seeds are easily spread.
  • Bush honeysuckle, Lonicera maackii and L. morrowii - Amur honeysuckle has passed flowering stage and the fruits are beginning to form, still small. Morrow's honeysuckle has bloomed and now has bright red and orange fruits.
  • Japanese honeysuckle, Lonicera japonica – Japanese honeysuckle is in full flower now.
  • Border privet, Ligustrum obtusifolium - Flowering stage has passed peak and fruits are beginning to form.
  • Purple wintercreeper, Euonymus fortuneii- Plants that have enough available light (high in tree canopies or in open wooded edges) are producing flower buds.
  • Chinese yam, Dioscorea oppositifolia , syn. D. oppositifolia - Plants are beginning to produce flower buds. The beginning of bulbil production still has not been observed. Plants are climbing rapidly into the tree canopy as new plants continue to emerge from last year's bulbils.
  • Teasel, Dipsacus follonum and D. laciniatus - Teasel is bolting and almost at the stage of flowering. In fact, you could likely find a few plants already in flower
  • Japanese stiltgrass, Microstegium vimineum – Stiltgrass is 4-5 inches tall and getting ready to start its rapid summer growth. Look for it to rapidly increase in height over the next few weeks.
  • Poison hemlock, Conium maculatum – Poison hemlock has been in full flower but many of the flower heads are starting to fade and produce seeds.

Southeast Illinois

Central Illinois

Northeast Illinois

Northwest Illinois

Follow the Illinois Invasive Species Awareness blog for more phenology reports as well as other invasive species news! (Kelly Estes)

Kelly Estes

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