It is a woody or semi-woody evergreen vine or running shrub to 12 ft (3.7 m) long, that climbs by twining. The leaves are oval, to 7 in (18 cm) long, and arranged in opposite pairs. Flowers are salverform (which means tuba shaped) having a slender tube with an abruptly expanded corolla. They are scarlet (sometimes white), about 1 in (2.5 cm) across and borne in dense terminal clusters to 5 in (12.7 cm) inches long. The fruit is unknown. Prefers full sun, but does best with some shade during the hottest part of the day in summer. Water frequently in summer, sparingly in winter. Hardiness: USDA Zones 10 - 11, does not tolerate frost. Requires a sturdy support like pergola. This evergreen climber is popular in warm, humid climates and can be used as an evergreen screen on a trellis or wall. The flowers are extremely showy and attractive to butterflies as well as people. Encourage branching and more flowers by cutting back previous season's growth to a suitable pair of buds.