Tribulus terrestris L.

Global description
 
Tribulus terrestris is a creeping species with compound, paripinnate and opposite leaves. The two leaves of the same pair are of different size. The whole plant is hispid. The flowers are solitary, located in the axils of short leaves. They are yellow. The fruit consists of five segments arranged in star and decorated with strong divergent spiny tines.
 
Cotyledons
 
The cotyledons are oblong, emarginate at the top. They are marked by 3 ribs emerging from the base. The petiole is 5 mm long and the blade is 7 to 10 mm long and 3 mm wide.
 
First leaves
 
The first leaves are compound and opposite. They carry 3 or 4 pairs of hispid leaflets.
 
Growth habit
 
The growth habit is prostrate, the end of the axes can sometimes be erect. The plant is usually branched from the base in several radiant axis, allowing it to grow in patches. Each axis measures 30 to 60 cm long but can reach over 2 m in favorable conditions.
 
Underground system
 
The plant has a taproot system, abundantly branched into fibrous secondary roots. It can reach more than 1 m deep.
 
Stem
 
The stem is cylindrical, finely striated longitudinally. It is green to red. It is covered with a strong pubescence of a mixture of long and short white hairs.
 
Leaf
 
The leaves are composed and opposite. Within each pair of leaves, one is less developed than the other. The larger leaves measure up to 6 cm long. On each side of the base of the petiole, is a linear leafy stipules, 3 mm long, covered with long white hairs, and quickly deciduous. The petiole is short (6 to 8 mm). The leaves are paripinnate, with 5 to 8 pairs of opposite leaflets. The terminal leaflets are smaller than those at the base of the rachis. They measure 5 to 10 mm long and 2 to 4 mm wide. They are sub sessile, oblong, and asymmetric at the base. The margin is entire. The lower side is more densely pubescent that the upper side.
 
Inflorescence
 
The flowers are solitary, located in the axils of shorter leaves.
 
Flower
 
They are carried by a pubescent pedicel shorter than the leaf. The calyx consists of 5 lanceolate sepals, 3 to 5 mm long, covered with long white hairs. The corolla has 5 obovate petals, yellow in color and measuring 3 to 12 mm long. The stamens are numerous and are as long as the petals.
 
Fruit
 
The fruits consist of five triangular segments arranged in star shape and becoming very hard at maturity. Each segment is indehiscent and glabrous to slightly pubescent. It is decorated at halfway with two strong divergent and spiny tines and have at the base 2 small tips. It may have a dorsal ridge roughly tuberculate. Each segment contains 3 to 5 seeds.
 
Seed
 
The seeds are fusiform with a pointed top. They are 2.5 mm long and are light colored.

Origin

Tribulus terrestris is native to the ancient world, from the Mediterranean area to Asia and all of Africa.

Worldwide distribution

This species was introduced into North America (USA) and South America. It is currently widespread in all tropical and warm temperate regions of the world, between 47 degrees north latitude and 35 degrees south latitude.

Algeria: A common species throughout the country up to the Sahara.

https://www.gbif.org/species/5421116