PlantNET Home DONATE TODAY | PlantNET Home | Search NSW Flora | Contact Us  
FloraOnline
Introduction
Plant Name Search
Index Search
Spatial Search
Identification Keys
Classification
Glossary
HerbLink (Type Images)
WeedAlert
Other PlantNET Sites
Other Data Sources
NEW SOUTH WALES FLORA ONLINE Printable Page

Genus Tribulus Family Zygophyllaceae
Common Name: Caltrop

Description: Annual or short-lived perennial herbs, usually hairy, mostly with elongated prostrate branches.

Leaves paripinnate with 3–12 pairs of ± oblong leaflets, opposite or alternate by abortion.

Flowers solitary, axillary, pedicellate. Sepals and petals 5, caducous. Petals yellow. Stamens 10 or rarely fewer by abortion. Nectariferous glands 5 between the calyx and corolla, 5 between the inner stamens and ovary. Ovary 5-locular, with 2–5 ovules per loculus (rarely 1 by abortion); stigma pyramidal to globose.

Fruit a schizocarp, separating into 5 (sometimes fewer by abortion) bony indehiscent usually spiny cocci [occasionally winged]; seeds without endosperm, separated by transverse or oblique septa that develop after fertilization.


Distribution and occurrence: World: c. 25 species, temperate to tropical regions of Europe, Africa, Asia, Australia. Australia: 11 species (9 species endemic), all mainland States.

Species can cause various disorders in sheep. The spiny fruits injure feet of animals and contaminate wool and stock-food.

Text by K. L. Wilson
Taxon concept:

 Key to the species 
1Stigma elongated, pyramidal; style no longer than stigma; spines on fruit well-developed; cocci 4–14 mm long2
Stigma hemispherical or globose, occasionally elongated but then style relatively much longer; spines on fruit not well- developed; cocci 2–5 mm long3
2Fruit with numerous spines; cocci 8–14 mm longTribulus eichlerianus
Fruit with 2 upper and 2 lower spines; cocci 4–8 mm long
                       Back to 1
Tribulus terrestris
3Style longer than stigma, often 2.5 times as long; petals 5–13 mm longTribulus micrococcus
Style much shorter than stigma, often nearly absent; petals 3–4 mm long
                       Back to 1
Tribulus minutus

  Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET