[nps.gov] Parasitism, Range, Proximity to Host Plant: Parasitism Green plants use chlorophyll to create their own food from sunlight and water through photosynthesis. California groundcone does not perform photosynthesis. Instead, it uses haustoria, specialized roots, to attach to and take nutrients from the roots of Pacific madrone trees (Arbutus menziesii) and manzanita shrubs (Arctostaphylos spp.). Although it is a holoparasite, meaning that it is fully dependent on its host for survival, there is currently no scientific evidence that it is harmful to its hosts.California groundcone grows in open mixed conifer woodlands and chaparral where madrone trees and manzanita shrubs are present. It often grows beside or on trails. Its range is scattered and extends from central and southern Oregon to Baja California (Mexico). It can grow at sea level to nearly 1830 m (6000 ft) elevation, depending on latitude. Roots of madrones and manzanitas can spread far from their main trunks or stems, so California groundcone may grow where its host is not apparently present. (link added by Mary Ann Machi)