Family: Rubiaceae

There are around 150 species in this genus of exotic, evergreen shrubs mainly from tropical America and the West Indies. Very few are in general cultivation. They have decorative, prominently veined foliage. Masses of white, pink or red flowers are borne in large trusses, in summer or autumn. Outside the tropics or subtropics, they are grown in an intermediate to warm greenhouse.

Species

R. amoena, from Mexico and Guatemala, is the species most often grown in the UK and Europe. Growing to around 3 m (10 ft), with a bushy crown, it has rounded clusters of fragrant, salmon to rose pink flowers at the branch tips.

R. odorata, to 2.5 m (8 ft), has orange-red, fragrant, autumn flowers.

R. strigosa is a smaller species, to 1.5 m (5 ft) high, with bright crimson flowers.

Cultivation

In the greenhouse or conservatory, grow in pots of soil-based potting compost. Plants need maximum light. Shade from direct, strong sun. Outdoors plant in a warm, sunny position with well-drained soil. Cannot tolerate heavy frost. Propagate from semi-ripe cuttings in summer, rooting them in a heated propagating case.

Climate

Zone 10 to tropical.