Cassia grandis

Cassia grandis.

Cassia grandis is just one of the pink or red flowered Cassias.
The Pink shower tree is seen in Brisbane streets and parks.
They are up to 30 m high with a straight trunk and smooth grey bark.
They have a rounded top with long, slightly arched branches.
They are deciduous or semi-deciduous.
There are tangled, woolly rust-coloured hairs on young branches.

The alternate leaves, around 25 cm long are on a petiole around 3 cm long.
There are very small stipules at the base of the petiole but they fall off early.
Leaves are pinnate with up to 20 pairs of leaflets and no terminal one.
The oblong leaflets, up to 6 cm long and 1.5 cm wide have a rounded base and tip.
The petiole, midrib and petiolules all have dense, short pale reddish-brown hairs.
The lower surface of the leaflets has longer white hairs mainly on the veins.
There are fewer and shorter white hairs on the upper surface.

Pendulous axillary inflorescences are unbranched and up to 25 cm long.
Each of the up to 40 flowers is on a pedicel.
The red midrib and pedicels are densely covered in short tangled white hairs.
The flowers, up to 3 cm wide have 5 free sepals that alternate with the 5 free petals.
The reddish sepals, around 6 mm long have dense short pale hairs on both surfaces.

The petals, up to 3.5 cm long have a short clawed base.
Initially red they age to pink and orange and finally fade to almost white.
Four are round to widely ovate while the fifth is elliptic and has a broad yellow
    stripe at the base that is up to 1.5 cm long.
There are hairs on the outer surface of the petals.

There are 10 stamens in 3 groups.
The lower 3 have ‘S’ shaped filaments up to 3 cm long with a swollen area on them.
These are fertile with 3 mm long anthers that open via short slits.
There are 5 stamens up to 1 cm long with straight filaments and 1.5 mm long anthers.
They may be fertile or sterile.
Above these are 2 minute staminodes only a few mms long.
All the anthers have hairs on them.

The long curved hairy ovary, with one locule is on a short stalk.
The short red style has dense white hairs on it.
The stigma is very small.

The fruit are tough, woody pods around 70 (50 – 90) cm long and around 4 cm wide.
They are cylindrical, indehiscent and mature from green to black and have no hairs.
The pods remain on the tree for up to a year.
Each holds up to 80 seeds lying transversely and separated by septa.
The flattened, ellipsoidal pale brown seeds are up to 2 cm long.

Other pink or red Cassias.

There are a number of species, varieties and cultivars known as Pink (or red) cassias.
These include the species:

    Cassia bakeriana (Pink cassia),
    Cassia grandis (Pink shower),
    Cassia javanica or nodosa, (Pink or Rainbow shower),
    Cassia marginata (Red Cassia),
    Cassia renigera (Burmese Pink Cassia).

Cultivars include:
    Cassia bakeriana x fistula (Apple Blossom Tree),
    Cassia fistula x javanica,
    Cassia fistula x grandis and
    Cassia javanica x grandis (Rainbow Shower with clusters of yellow to pink flowers).