Cuphea micropetala

Native to central and southwestern Mexico, this plant is an upright woody perennial shrub. Its stems are often reddish purple, and its leaves are narrow and pointed. The tubular calyx, rather than the tiny white or yellowish petals, provides most of the flower’s color. It begins yellow-green with a red base and becomes red as it ages. The stamens project beyond the tube, and the fruit is a capsule containing many seeds. In cultivation, it produces flowers along the upper stems in summer and fall. Photographed in Virginia.