A round patch of Arum, about 3 feet across. Didn't see it anywhere else in the park except for right there.
Commentary
None
Remedy
Italian arum can be difficult to eradicate once established. Make sure to wear gloves and long sleeves and pants when removing it, as its sap can cause skin irritation. Do not compost or put in your yard debris, as this can lead to spreading of tubers which can grow into new plants. Home control methods can include carefully digging out the tuber and any daughter tubers and disposing in the trash. Cutting and disposing of the berries in the trash can help prevent spreading to new sites. Herbicide trials are still inconclusive, please contact your local Soil and Water Conservation District if you are interested in chemical control.
On the left side of the trail as you're heading up the trail from the Marquam Shelter, near the old house foundation.
Expert Reviewer
Mrs. Lindsey Wise Oregon Biodiversity Information Center, inr.oregonstate.edu/orbic Oregon iMapInvasives Institute for Natural Resources Portland State University