Family: Caesalpiniaceae

This genus of annuals, sub-shrubs, shrubs and trees is now divided into several groups. In fact a great many species of familiar cassias have now been placed in the genus Sennu. Natives of tropical and temperate regions around the world, including North and South America, some are deciduous, some are evergreen. Generally they have pinnate leaves and showy clusters of flowers. The seed pods are mostly flattened or cylindrical, and sometimes winged.

Species

C. brewsteri, cigar cassia, is found growing in the rainforests of Australia. This tree reaches around 9 m (30 ft), with long sprays of yellow and red flowers. The pod, up to 30 cm (12 in) long, is shaped like a large cigar.

C. fistula, golden shower, is a slender tree which grows to 9 m (30 ft). It has fragrant, pale yellow flowers in sprays 30-45 cm (12-18 in) long and cylindrical pods, which are often as long as 60 cm (24 in).

C. grandis, pink shower, has lateral sprays of large, rose-coloured flowers and rather flattened pods, 60 cm (24 in) long. The tree grows to 15 m (50 ft).

C. javanica, Java shower, is a wide-spreading tree which can grow to 10 m (33 ft) tall under cultivation. It has showy sprays of rose-pink flowers above the leaves, and cylindrical pods which can be 60 cm (24 in) long.

Cultivation

In frost-prone climates, grow in an intermediate or warm greenhouse or conservatory, in pots of soil-based potting compost. Maximum light is needed. Outdoors, most species prefer a moderately well drained soil containing plenty of organic matter. Some will tolerate a little shade. Propagate from seed sown in spring. Hard seeds may need a light abrading with sandpaper before soaking overnight in cold water. Prune back after flowering to encourage bushy growth or to avoid seed setting. The tree-like species will be too tall to prune.

Climate

Zone 10 and above for the following species.