Land Plants - invasive

Italian Arum (Arum italicum) on Mar 13, 2015

Submitter has sample
EDRR Status: Local expert notified

Description of specimen

I have positively identified it as Arum italicum. I have been identifying plants for over 20 years.


Dear Mrs. Carothers,

I would like to thank you for contacting the Oregon Invasive Species Hotline regarding the Italian arum (Arum italicum) infestation near your property. Controlling invasive weeds can be a difficult task, so I commend you on taking the initiative to improve your property.

Italian arum is known to be a very problematic plant, and is difficult to control. Although this plant is aggressive, it is currently not listed as a noxious weed in Oregon, and is sold commercially. As such, this is a species that is not targeted for control efforts by the Clackamas Soil and Water Conservation District’s WeedWise program.

That said, this species is a listed weed by the 4-County Cooperative Weed Management Area and we encourage landowners to control this plant when possible. As a relatively new invasive, there is very little known regarding control efficacy. The current Best Management Practices for control of Italian arum are removal by digging. Removed material should be disposed of as trash and not composted.

In your report you mentioned that the infested area occurs within the right-of-way. Although, this area is outside of your fenced yard, Clackamas County only manages these areas for line of sight and for road maintenance. Additional management of the vegetation within these areas is the responsibility of the adjacent landowners.

As a new invasive weed, information about the control of Italian arum is developing rapidly. Please contact me if you have questions about Best Management Practices. Although, we are unable to control this weed on your behalf, we will do everything we can to make your efforts more successful.

As a candidate for noxious weed listing, your report will also help with future, containment, control and eradication efforts. So thank you for your time spent reporting this plant.

Thanks again for taking the time to report this invasive weed to the Oregon Invasives Hotline. Please feel free to contact me if you have any more questions.

All the best,

Samuel Leininger
WeedWise Program Manager

Samuel Leininger
March 31, 2015, 1:43 p.m.