Common name: Caltrop, Cat-head
Tribulus terrestris L. APNI*
Description: Prostrate herb with branches to 80 cm long.
Leaves with 4–8 pairs of leaflets; leaflets ± oblong, 4–12 mm long, to c. 4 mm wide.
Sepals 2–4 mm long. Petals 3–6 mm long, 1.2–2 times as long as sepals. Stigma elongated pyramidal; style no longer than stigma.
Fruit slightly hairy; cocci 4–8 mm long, wrinkled-muricate dorsally, with 2 very divergent spines 3–8 mm long above, and 2 shorter basal spines 1–4 mm long pointing downwards; seeds 2–4 per coccus.
Distribution and occurrence: Widespread weed, mostly along tracks and around habitation, especially in inland districts. Native at least to Mediterranean region but now cosmopolitan weed.
NSW subdivisions: *NC, *CC, *NT, *CT, *ST, *NWS, *CWS, *SWS, *NWP, *SWP, *NFWP, *SFWP, *LHI
Other Australian states: *Qld *Vic. *W.A. *S.A. *N.T.
Inland specimens with larger, more rounded fruit, and a small, more rounded fruit with somewhat shorter spines may represent 2 separate species (possibly native).
Text by K. L. Wilson
Taxon concept: Flora of NSW 3 (1992)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.