Turk's Cap

Malvaviscus arboreus flowers like a hibiscus that never quite opens. Turk's Cap carries bright red pendent flowers whose petals stay furled around a projecting staminal column, and it produces them almost continuously through the warm season on a soft, broad-leaved shrub from the American tropics.
It flowers in shade, which most red-flowering shrubs will not do, and that makes it valuable under canopy trees and along the shaded side of a building.
Turk's Cap is one of the few genuinely shade-tolerant shrubs that will hold red flower colour for most of the year.