If you’ve spent time in the woods in southern Oregon, you’ve probably run into these brown or purple-colored 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. The California groundcone (Boschniakia strobilacea) is a member of the broomrape family that parasitizes the roots of nearby madrone trees and manzanita shrubs. Because it’s a parasite, it doesn’t make its own energy and thus does not have green leaves. But it does have flowers. 

These stick out from the bracts in spring. The bracts look very similar to cone scales from a conifer tree, hence the name ground “cone”. There is another groundcone species found near the coast and further north that is parasitic on salal. 

Ground cones do not have roots – instead they have haustoria, root-like organs that penentrate the roots of their host. True and dwarf mistletoe plants also have haustoria. To the best of my knowledge, ground cones do not represent a significant threat to the health of their hosts. 

Related Content from OSU Extension

Ask an Expert

Have a Question? Ask an Expert!

Ask an Expert is a way for you to get answers from the Oregon State University Extension Service. We have experts in family and health, community development, food and agriculture, coastal issues, forestry, programs for young people, and gardening.

Ask Us a Question