Caltrop

Family: Zygophyllaceae
Scientific name: Tribulus terrestris
Description: Plant Form: Spreading annual herb. Size: Up to 80 cm long. Stem: Reddish-brown to green, many branched, scrambling low to ground. Silvery appearance due to covering of hairs. Leaves: Compound of leaflet pairs, between 4-7 leaflets per leaf, plus single leaf at ends, opposite on stems. Flowers: Bright yellow, 5 petals opening in the morning, which are usually lost quickly, single at leaf junction. Fruit and Seeds: Nearly spherical woody hard burrs to 1 cm long, with sharp rigid spines up to 8 mm long. Break into 5 wedge-shaped nutlets with 2-4 seeds. Habitat: Roadsides, pastures, neglected areas, cropping areas. Distinguishing Features: There are many similar species in the genus Tribulus, and debate over whether many are native. Tribulus minutes and T. micrococus are very similar but much smaller or no spines on the nutlets. Weed Status: Priority Weed Weed Type: Agricultural, Common Lifeform: Herbaceous

Example images for this weed