CERATOSTIGMA. Himalayas to Africa. Charming relatives of the common plumbago (Plumbago auriculata). They are twiggy perennials and shrubs with attractive pointed-oval leaves, often tinged with red in cooler weather. In late summer and fall they carry many clusters of blue flowers, flaring widely from a narrow tube, at the shoot tips. Sun or light shade, most soils, moderate watering. Their hardiness varies as shown below.
griffithii. Mounding in habit, growing 2-3' tall. It is thickly clothed with bluish green leaves about 1" long. The flowers are up to 1" across and painted bright, true blue. The plant is basically evergreen, though nipped back at times by hard frosts. 10oF or less.
willmottianum. Chinese plumbago. A spreading 2-4' shrub with reddish, zigzag stems and deep green 1-2" leaves. These are often vividly colored in fall. Bright blue 1" blossoms are clustered at the shoot tips over most of the summer and early fall. 10oF or less.