If you’ve spent time in the woods in southern Oregon, you’ve probably run into these brown or purple cone-like organisms protruding from the forest floor or a nearby road cut. Many have wondered what these strange items are: cones from trees? Plants?
Actually, they are plants – parasitic plants, to be exact. This perennial herb known as California groundcone (Kopsiopsis strobilacea) is a member of the broom-rape family that parasitizes and causes large knobs on the roots of nearby madrone trees and manzanita shrubs. It is slender, can grow to be one foot tall, and ranges from southern California to southern Oregon. Because it’s a parasite, it doesn’t make its own energy and thus does not have green leaves. But it does have flowers.
The yellow and purple flowers stick out from the bracts in spring. The bracts look very similar to cone scales from a conifer tree, hence the name ground “cone.” Another groundcone species is found near the northern coast and is parasitic on salal.
Groundcones do not have typical roots; instead, they have haustoria, root-like organs that penetrate and wrap around the roots of their host to absorb water and nutrients. True and dwarf mistletoe plants also have haustoria. Because madrone and manzanita can spread far from the main trunks, California groundcone may grow where its host is not apparently present. Although groundcones are fully dependent on their hosts for survival, there is currently no scientific evidence that it is harmful to the host.
