Distribution of senna seymeria (Seymeria cassioides) a root parasite on southern pines

In 1969 senna seymeria [Seymeria cassioides (J. F. Gmel.) Blake], an annual of the figwort family (Scrophulariaceae), was found to be parasitic on roots of slash pine (Pinus elliottii Engelm.). Subsequent tests showed that the plant is an obligate parasite on at least three species of southern pines and is apparently selective for pines only. A southwide survey indicated that senna seymeria is most common on moist, sandy sites of the Lower Gulf and Atlantic Coastal Plains.