Cassia fistula Seeds | Golden Shower Tree
LATIN NAME: Cassia fistula
COMMON NAME: Golden Shower Tree
Plant Profile
The foliage is compound to the second degree: each leaf carries several pairs of pinnae, and every pinna bears a row of smooth-edged oval leaflets with no single terminal leaflet at the tip. That even-pinnate arrangement is one character used to separate Cassia from Senna. Flowers sit in axillary racemes rather than a terminal cluster, with five irregular yellow petals and ten stamens of unequal length.
For most of the last century Cassia was an enormous tropical genus. Molecular work and the reorganisation of the tribe Cassieae broke it apart, and most of the old species moved out into Senna. Cassia fistula stayed behind because it is the conserved type of the name itself. Both names circulate in the trade, and the tree is identical either way.
It is planted for one spectacle and one silhouette, and it is generous with both. On tropical avenues it makes a light, high crown that lets grass grow beneath, and in temple grounds it supplies shade without a heavy root plate. In Kerala the flowering falls at Vishu, and clusters of the yellow flowers are arranged as festival decoration.
Science & Biotechnology
The dark pulp is the classical drug material, and its activity is anthraquinone activity. Rhein and a family of sennosides sit inside a sugary matrix, which is why the pulp tastes faintly sweet rather than bitter. The same compounds turn up in rhubarb and in the Senna species that left the genus, a neat demonstration that chemistry follows the tribe rather than the label on the pot.
The petals owe their colour to carotenoid and flavonol pigments, and the seed coat holds galactomannan-type storage polysaccharides of the kind studied in other legume seeds. Leaf and bark extracts have drawn antioxidant interest, but these are laboratory lines of inquiry rather than home preparations.
Uses & Benefits
The old trade name is literal. Once the flowers fall, the tree sets cylindrical pods that ripen from green to a deep sooty brown and hang straight down for months. Thin transverse walls divide each pod into chambers, and every chamber holds a flat brown seed bedded in a sticky dark pulp. A pod runs longer than a human forearm, so the tree that was a shower of gold becomes a row of dark drumsticks.
Growing from Seed
The seed coat is the real obstacle. Fresh seed has a hard coat that is glossy and impermeable to water, so break that barrier before sowing: rub a patch against fine abrasive paper, or nick it once with a file, then soak the seed in lukewarm water until it visibly swells. Sow into a mix of two parts sieved compost, one part coarse sand and one part perlite, pressing each seed in about twice its own thickness deep.
Keep the tray warm, humid and in bright filtered light, and water from below so the seeds do not float free. Move the seedlings on once each has pushed out its first two true leaves, into deep pots, because the taproot straightens quickly and a shallow container produces a bent root. Plant out at the start of the wet season.
Train young trees by removing crossing limbs and lifting the lowest branches rather than by shortening the leader. Feed with a balanced granular fertiliser as new growth starts, and keep a circle of mulch pulled back from the trunk. Leaf fall in the dry season is normal. In cooler subtropical gardens, plant against a warm wall and protect the first winters.
Stem borers occasionally attack young trunks; look for sawdust at the base of a limb and cut out the affected wood. Pods attract seed beetles, so collect them for seed as soon as they darken instead of leaving them to split. In heavy, poorly drained soil the tree is prone to root rot, which is the argument for planting on a raised mound.
Our Take
This one rewards patience more than fuss: break the seed coat, give it warmth and depth, and the tree does the rest. For a golden avenue, sow it beside Cassia javanica and Cassia bakeriana, whose pink and white racemes overlap with it through the warm season, and add Senna alata where you want a lower, shrubby companion from the same tribe.
Related Reading
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