swamp azalea: shrub growing in swamps throughout the eastern United States and having small white to pinkish flowers resembling honeysuckle
rhododendron: any shrub of the genus Rhododendron: evergreen shrubs or small shrubby trees having leathery leaves and showy clusters of campanulate (bell-shaped) flowers
eccentricity: (geometry) a ratio describing the shape of a conic section; the ratio of the distance between the foci to the length of the major axis