A mixed group of annuals, perennials and subshrubs mostly from North America. These plants are hemiparasites, meaning they are partly parasitic on the roots of other plants, although they seem to cause very little damage to their hosts and, indeed, sometimes grow well enough without a host (e.g. in a pot by themselves). Penstemons are recommended as hosts, They produce dense spikes of inconspicuous flowers but colour is provided by their showier bracts.