Hypericum ascyron (syn. pyramidatum), Giant St. John's Wort

 An herbaceous, upright, deciduous perennial that can reach 2-5 feet tall. In mid-summer, showy display of 2-inch diameter yellow flowers that form pyramid-shaped clusters at branch ends. Easily grown in moist, well-drained soils in full sun to part shade but will tolerate some drought. Forms rhizomatous clumps rather than spreading rampantly like the common, much-maligned Hypericum perforatum.