Ask Dr Bec: Why do Cat-heads hurt so much when you step on them?

Why do Cat-heads hurt so much when you step on them?

There’s nothing worse than walking barefoot through what you think is lush grass, only to step on a cat-head, also known as Caltrop or Tribulus terrestris.

These small seeds can deliver a surprisingly painful jab due to their clever design, featuring sharp, rigid thorns on seed pods that easily pierce the skin.

Caltrop seeds are specialised structures developed by plants in dry, sandy habitats like deserts.

Their spiky shape serves a vital purpose beyond appearance—it’s a survival strategy.

By hitching rides on passing animals or embedding themselves in the ground, Caltrop plants ensure widespread distribution of their seeds.

Sheep and goats readily consume this weed, but grazing on mature plants with intact seed heads for more than 14 days during summer has been linked to cases of nitrate poisoning and photosensitivity.

Caltrop seeds can remain dormant in the soil for up to five years.

Each of these seeds, known for their hard, spiky thorns, contains about 20 seeds, potentially yielding up to 8000 seeds from a single plant.

Despite their unpleasantness, understanding the resilience and strategy behind weeds like Caltrop can provide valuable insights for scientists.

By studying how these plants adapt and thrive in harsh environments, researchers can discover methods to enhance the resilience of important food crops.

This knowledge may lead to advancements in agricultural practices, allowing crops to withstand challenging conditions such as drought, poor soil quality, or extreme temperatures.

You can use chemical sprays to try to control Caltrop in your lawn but the most effective way to is to carefully remove it by hand, ensuring you extract the taproot as well, and dispose of it in your red-lidded bin.

Avoid putting it in your green bin as this will only spread them more widely!