information
Memorial Day closure

Most City of Portland offices will be closed Monday, May 27, in observance of Memorial Day.

Invasive Plant: Italian Arum

Information
Photo shows green plant with long, waxy leaves with white stripes.
Italian arum, a British native, is another commonly swapped species with a reputation for being extremely difficult to remove.
On this page

At a Glance

Scientific name: Arum italicum (Italian arum; lords and ladies)

Why Are We Concerned?

There are currently no highly effective means of getting rid of Italian arum. Italian arum infestations can lead to reduced plant and animal diversity as other species are displaced.

How Does It Spread?

Italian arum is spread by seed, but, more importantly, through small bulblets, which are easily spread in disturbed areas. The berries, which float, can also be dispersed by water. Italian arum seeds and bulblets are moved by:

  • Soil movement
  • Gardeners
  • Running water

What Does It Look Like?

Photo shows green plant with long, waxy leaves with white stripes.
Italian arum has dark green, waxy leaves with white stripes.

Italian arum has dark green, waxy leaves with white stripes. It is a perennial that commonly reaches 12-15 inches. In late summer, it produces small clumps of orange berries.

Are There Any Look-alikes?

Out of the flowering season, Italian arum can be confused with other members of the Arum family, particularly calla lilies. In flower, of course, those plants are unlikely to be mixed up.

How Do We Deal with It?

  • Manual. Digging up Italian arum is time-consuming and requires careful attention to detail, as well as regular monitoring. Manual management is only recommended on small patches. Excavated soil and bulbs should be go in the trash, not in compost or yard debris.
  • Herbicide. No effective herbicide treatments are known.

How Can Folks Help?

Use caution and wear gloves. Ingestion of plants could cause health problems such as sickness and may require medical treatment. Contact with plant parts may cause severe skin irritation for sensitive individuals. 

Italian arum is not a species that the city is currently managing on private property. Private property holders are, however, strongly encouraged to manage and properly dispose of Italian arum. Do not trade this species with other gardeners.