Cassia brewsteri

Brewster's cassia


Cassia brewsteri

F.Muell. 1864

pronounced: KASS-ee-uh BREW-stir-eye

(Fabaceae — the pea family)

subfamily: Caesalpinioideae - the cassia subfamily

synonym — Cathartocarpus brewsteri

F.Muell 1959

pronounced: kath-ART-oh-kar-puss BREW-stir-eye

common names: Brewster's cassia, cigar cassia, Leichhardt bean

native 4Cassia (or casia) is the Roman name of a tree with aromatic bark, perhaps the wild cinnamon. It would appear that the specific honours Sir David Brewster (1781-1868) a leading British physicist, who, among many other investigations and inventions, was the inventor of the kaleidoscope. In the synonym, Cathartocarpus is from the Greek καθαρτης (kathartés), a cleanser, purifier, and καρπος (karpos), fruit . Von Mueller found the type species of this plant on the banks of the Burdekin River, not far south of Townsville.

This is a variable, small to medium sized tree with very attractive, fern-like foliage, and very decorative spikes of hanging yellow to red flowers in autumn. It is found along the Queensland coast from about Cairns south, in a few places on the northern NSW coast, and occasionally on the central coast of Western Australia. It mainly grows in open forest, but also occurs in vine thickets. The young tree photographed has been planted in a Picnic Bay garden.

The leaves are compound, with 2 - 6 pairs of leaflets, each up to about 4.5 cm long, oblong-elliptic in shape, with the apex retuse. The upper surface is glossy or waxy, a darkish green, and the under surface whitish green. The leaflet petiolules are grooved on the upper surface, and the lateral leaflet veins are looping. The leaf petiole is swollen at its junction with the twig.

The infloescence is a terminal, pendulous raceme, 7  - 20 cm long, bearing 10 - 50 flowers. Each flower is about 10  - 18 mm in diameter. The calyx is hairy on the outside, and there are 5 petals. There are either 10 stamens with no staminodes, or 7 stamens with 3 staminodes.

The fruits are cigar-shaped pods, up to 45 cm long, somewhat compressed, or more-or-less circular, in cross-section. They are often purplish in colour, with a glaucous bloom. They are ribbed between the seeds, which are enclosed in a corky disk. The seeds are often heavily parasitized.

Although the tree comes from wet tropical areas, it will thrive in other tropical and sub-tropical climates. It can grow anywhere from 2 to 8 metres tall, and likes a fair amount of sun. It likes regular watering until it is well-established, but later becomes quite drought-tolerant. It will also tolerate a light frost (down to about -2ºC).

Brewster’s Cassia also makes an attractive container tree, especially in cooler climates. The only specimen of the tree I know on Magnetic Island is the sapling pictured, so I have shown pictures of a mature specimen from southern Queensland.


Photograph taken in Picnic Bay 2016, Brisbane 2017
Page last updated 31st October 2018