Description:

Italian arum is an herbaceous perennial in the Araceae family. The leaves are shaped like arrowheads and are dark green and glossy, with light green veins. The flowers are unpleasant smelling and fingerlike, growing into berry clusters that change from green to orange-red. The plant grows from underground tubers, so it regrows easily when cut or mowed.

Life cycle:

Perennial

Height of mature plants

1 – 1.5 feet tall

Flower color:

White to yellow

Bloom time:

April – June

Look-a-likes:

Arum lily (Zantedeschia aethiopica) and stink lily (Dracunculus vulgaris) can have a similar appearance, but all lack the white variegated leaves typical of Italian arum.  Out of flowering season, Italian arum can be confused with calla lilies. However, once the plant has produced flowers and/or berries, the difference is apparent.

Habitat:

Italian arum grows in many habitats including forests, disturbed urban areas, yards, riparian zones, and wetlands. It grows in partial to full shade, and although it prefers moist hummus soils, it can grow in most soil types and is drought tolerant once it establishes.

Impacts:

Italian arum was originally used as an ornamental ground cover, but is considered invasive due to difficulties in controlling it and its ability to spread rapidly. It is a poisonous plant that invades forests, riparian areas, urban areas, and wetlands. All parts of this plant can cause skin irritation or illness to both people and wildlife. It is extremely difficult to control, spreads rapidly by both seeds and root fragments, and can shade out other plants. While birds often disperse the seeds, it also spreads in yard debris and contaminated compost.

Noxious Weed Listing:

• WeedWise: Maintenance
• State of Oregon: Not Listed
• State of Washington: Class C
• Four County CWMA: Class B
• Columbia Gorge CWMA: Class B

Origin:

Asia, Europe, and North Africa

Links:

Washington Noxious Weed Profile
Washington State Italian Arum Brochure
National Park Service Plant Alert