pronounced: KASS-ee-uh species puh-LOO-muh range
Cassia (or casia) ais the Roman name of a tree; Paluma Range is a mountainous area about 100 km north of Townsville. At the summit is Mount Spec, which rises to about 1000 m and is covered in luxuriant rainforest, which was once heavily logged. Paluma Dam, near the summit, holds a reservoir that contributes to Townsville’s water supply, piped down the coastal strip to Townsville in a gravity-fed system.
This is a rare native Cassia that grows in monsoon forest, rainforest, vine forest, open forest and woodlands at altitudes from from about 50 m to 750 m. It is a shrub or small tree growing to 10 m or more tall, with its trunk and larger branches having grey, flaky-tessellated bark. Its distribution is not confined entirely to the Paluma area: it is also found further down the Queensland coast, to about Mackay.
The leaves are paripinnate, with 5-8 pairs of leaflets that are light green on the upper surface and dull green on the lower, quite large for the genus, 4-10 cm long by 2-4 cm wide. They are glabrous, and new growth is often maroon in colour, making the tree quite distinctive, and very attractive.
It is also very attractive and quite spectacular when in flower. Pendant yellow racemes up to 40 cm long hang from the underside of branches, each bearing up to 80 flowers. The calyx is green, and the 5 petals yellow, and the anterior petals sometimes have a red base. Fertilization is probably carried out through buzz-pollination by solitary bees.
The fruit is a long round reddish brown pod that may be either glabrous or pubescent, and is 35-60 cm long by 1.5-2 cm in diameter. Its pedicel is quite long, up to about 20 cm.
The tree was discovered by Yuruga Nursery, and makes a good garden specimen instead of other imported species such as Cassia fistula. In normal garden conditions, it rarely grows above 8 m in height.
It is a food plant for the Lemon Migrant butterfly, Catopsilia pomona.
The tree is tolerant to fire, regrowing from the base. It is thought that fire may stimulate seed germination. The seeds float, and may be carried to new locations by water.
There is much confusion about its taxonomy. Some authorities place it as a part of Cassia queenslandica, but others dispute that, pointing out that the seed pods are entirely different – totally round in C. queenslandica and ribbed in sp. Paluma Range. C. queenslandica also lacks the reddish tinge to the new growth of leaves. At one stage it was thought to be a form of C. marksiana, which grows in the nearby Mount Fox area.
The young tree photographed has been planted in a Picnic Bay garden.
