Puncture Vine (Caltrop)

Puncture vine (Tribulus terrestris, bhakra or gokhru) is the low, spreading caltrop that colonises bare, hot, disturbed soils across the Punjab plains, the Sindh coast, and the Balochistan highlands. It is a prostrate annual with hairy trailing stems, small yellow five-petalled flowers, and the hard spiny fruit that gives it its English names.¹ The same fruit, dried as gokhru, is one of the more important tonics in local herbal medicine — while the living plant is a weed to watch around stock.

Where it thrives

This is a plant of warm, dry, broken ground. Native to warm-temperate and tropical southern Eurasia and Africa, it springs up on bare arid soils, roadsides, overgrazed range, and the edges of cultivation, and it has become a weed worldwide on exactly that kind of disturbed land.¹ The recumbent, branching stems run up to about a metre from a central root, hugging the surface, so the plant tolerates heat and trampling and seeds prolifically on ground that has been opened up.¹ It is at home through the hot season across the plains and arid zones of Pakistan.

Role in the system

In honest syntropic terms it is a pioneer coloniser of bare soil — one of the first things to green a scalped or overgrazed patch — rather than a plant you would introduce. Its prostrate cover does shade a little bare ground and its soft early growth can be cut as thin mulch, but its hard, spiny seed and its toxicity to stock mean it is best read as an indicator of disturbance and a medicinal harvest, not a guild component. The presence of dense puncture vine usually says the ground is bare and overgrazed and wants rest and cover; for the wider grazing logic see livestock in the mature canopy.

Uses and medicine

This is where the plant earns its keep. The dried fruit, gokhru, has long been used in Unani and Ayurvedic practice as a diuretic, anti-urolithic, and general tonic, and the fruit is given for urinary disorders and sexual dysfunction.² Modern work attributes much of that to saponins — protodioscin is the main one — and to flavonoids, and the fruit is well documented for its diuretic activity.² The fruit is gathered from the wild plant and the harvest is real, even though the standing weed is a nuisance.

Cautions

Two hazards matter on a farm. First, the fruit: its sharp spines puncture bare feet, animal hooves, and bicycle and cart tyres alike. Second, and more serious, the plant is strongly toxic to grazing sheep, where it causes a liver-linked photosensitivity — locally called geeldikkop — that can bring skin necrosis, loss of lips and ears, blindness, and death in young animals.¹ Keep heavy stands away from grazing sheep. Note too that, unlike the toxic fodder plant, standardised tribulus extracts taken at usual human doses have not been convincingly linked to liver injury — the danger is to the animal in the field.³

Sources

1. Colorado State University, Guide to Poisonous Plants. “Puncture vine, goat’s head, caltrop (Tribulus terrestris).” CSU.
2. Saeed, M., et al. (2024). “Promising phytopharmacology, nutritional potential, health benefits, and traditional usage of Tribulus terrestris L. herb.” Heliyon / PMC.
3. National Institute of Diabetes and Digestive and Kidney Diseases. “Tribulus.” LiverTox, NCBI Bookshelf.