Kapok signals seasonal changes

Many Katherine region plants are deciduous once the wet season rains fade. Herbs and grasses set seed and die, lilies and vines pull back into underground stems and bulbs.

Even large trees lose some or all their leaves as protection against the drying winds and hot temperatures that will come before the start of the next rainy season.

The stunning Cochlospermum fraserii, or Yellow Kapok is no exception. In the wet season this unremarkable little tree is covered in large, soft green leaves, blending in well with the tall grasses that usually surround it.

These leaves have an important job to do, creating all the food that the plant will need to see it through the hard times to come, but they lose water while they make tucker so when the rain stops, the tree cuts its losses and drops the leaves, protecting itself during the dry times.

The grey bark of the Kapok trunk is not bare for long though. Bright yellow flowers burst from the tips of the branches, creating splashes of colour that create a stark contrast to the grey-brown of the dry grasses and empty slopes around them. 

For many Indigenous people across the Top End of Australia the Yellow Kapok is an important plant. Its bright yellow flower petals have a slightly spicy taste and are good to eat when they are newly open and the tap root of young plants has a taste and texture like a radish.

The unripe seeds make a yellow dye when they are crushed while white fluff from a ripe seed pod can be used to pad a baby’s carrier or as part of a ceremonial costume.

Across its range the Kapok has another, more important use as an indicator of seasonal change. Its obvious physiological changes mark changes in weather that correspond to other important things.

Freshwater crocodiles and many turtles have started to lay their eggs in holes dug in sandy river banks, giving the little ones more than enough time to grow before the water levels rise with the wet.

The flowering of the Kapok is a great indicator that the egg laying has begun in earnest while the ripening and opening of the seed pods show that the eggs are starting to hatch.

Seasonal changes in our landscape can be subtle but they can tell us stories about the things that we cannot easily see.