Tribulus occidentalis

Tribulus occidentalis, common name perennial caltrop,^[1] is a species of flowering plant in the family Zygophyllaceae, which is native to Australia, and found in Western Australia,^[1] Queensland,^[2] South Australia^[3] and the Northern Territory.^[4] However, Robyn Barker asserts that it is confined to the west coast of Western Australia.^[5]

Tribulus occidentalis
Fruit
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Zygophyllales
Family:	Zygophyllaceae
Genus:	Tribulus
Species:	T. occidentalis
Binomial name
Tribulus occidentalis R.Br.

It is a prostrate perennial herb, covered in long shaggy hairs and growing from 2 cm to 10 cm high. The leaves occur in pairs, and have leaflets in 7 - 10 pairs. The fruits have many spines, which are from 4 to 8 mm long. It grows on sandy soils and its yellow flowers can be seen from February to November.^[1]

It was first described in 1849 by Robert Brown, from a specimen collected on the "west coast of Australia, or on some of its islands, in the Voyage of the Beagle."^[6][7] There are no synonyms.^[8]