The exquisite dark purple flowers with nearly black calyces appear constantly from early spring until frost. ‘Amistad’ has many advantages over other S. guaranitica cultivars. It is sterile, meaning more blooms and no chance of seedlings in the garden. ‘Amistad’ is also more compact and has a fuller habit then other S. guaranitica types. The flowers are a magnet for butterflies and hummingbirds. From the Sunset Western Garden Collection.