These Central American natives are some of autumn's showiest plants, especially in the Tropical South, where they appreciate a little afternoon shade. Hummingbirds and butterflies frequent the blossoms. If given moderately fertile, well-drained soil, they need little care. They are very tender to coldstems and leaves blacken with the first touch of frost. However, they often come back from the roots in the Coastal and Tropical South; elsewhere, treat them as annuals or overwinter indoors. Easily propagated from stem cuttings of mature new growth.
O. callistachyum. PURPLE FIRESPIKE. Grows as much as 8 ft. tall, featuring 10- to 12-in. spikes of purple blooms.
O. tubaeforme (O. strictum). FIRESPIKE. Forms a multistemmed mound to 6 ft. tall and about half as wide, with shiny, deep green leaves that are oval, pointed, and up to 6 in. long. Stunning, foot-long spikes of small, tubular, fiery red flowers crown the foliage for weeks, beginning in late summer and continuing through the fall.