Broad-leaved Dock is a perennial plant native to Europe, but has become naturalized world wide. It is an invasive species with a high potential to out compete native plants, primarily because of massive seed production. It is considered to be a noxious weed in many places, but is not yet listed as one in the PNW.
When Rumex obtusifolius is large and mature it is unmistakable, with ovate leaves 10-16” long by 4-6” wide. Younger plants can be differentiated from other Rumex spp. by the combination of a lack of arrow-shaped leaves and the presence of spiny tepals.
This plant is a known larval host for the butterfly Lycaena helloides (Purplish Copper), the moths Hyles lineata (White-lined Sphinx Moth) and Resapamea passer (Dock Rustic Moth), and the leaf beetle Gastrophysa cyanea (Green Dock Beetle).
It is considered edible, as a bitter salad herb, but does contain large amounts of oxalic acid, so care should be exercised. This is particularly important for folks prone to forming kidney stones.
Size- Up to 4’ tall
Habitat- Damp, disturbed ground
Range- Region wide; more common west of Cascades
Blooms- Mid to late summer.