Odontonema callistachyum

The purple firespike answers a quiet complaint of the warm-climate gardener, that the tropical border runs to reds and hot corals and forgets the cooler end of the spectrum. Odontonema callistachyum carries erect spikes of tubular, lavender-to-amethyst flowers at the tip of nearly every branch, each spike lengthening to almost a foot as the buds open in succession from fall into spring. The genus name joins the Greek odous, a tooth, with nema, a thread, for the small toothed filaments within the bloom, while the epithet callistachyum means, simply and accurately, beautiful spike. The leaves are broad, glossy, and faintly fleshy, a lacquered dark green that holds the plant together as a handsome mound even between flushes.

Native to Mexico and northern Central America, the shrub climbs to fifteen feet in frost-free country, where the winter-long bloom feeds hummingbirds and butterflies through the dry months when little else is working. Robert Lee Riffle, whose book The Tropical Look remains a touchstone for gardeners chasing jungle effects in temperate ground, wrote that this species should be more regularly planted in warm regions than it is, and anyone who has watched the purple spikes glow against dark foliage in December will understand the frustration behind the sentence.

Woodlanders grows this firespike from stock obtained from JoAnn Breland at Hampton Park in Charleston, South Carolina, a plant that has shown real promise for the Southern garden. At the cold edge of the range the top growth dies back and returns from the root, so mound sand over the crown and mulch well in late fall, and the shrub should prove root hardy through zone 8. Farther south, in zones 9 to 11, the plant holds evergreen and builds steadily toward full stature.

Set the purple firespike where the cool spikes can be read against something darker, at the back of a shaded border, along a courtyard wall, or in a large container that can be carried under cover as frost approaches. Partial shade suits the plant well, sparing the broad leaves from the worst afternoon glare, and a rich, moist, well-drained soil keeps the foliage lush. Pair with gingers, hibiscus, and bold-leaved bromeliads for a layered subtropical planting, and site the shrub within sight of a window or a seat, where the winter hummingbird traffic becomes part of the show.