Tribulus terrestris L.

Zygophyllaceae, E. Launert. Flora Zambesiaca 2:1. 1963

Morphology General Habit

Annual herb, extremely variable in habit, with spreading prostrate and usually decumbent branches, ± pubescent, villous or hispid, sometimes glabrescent in all vegetative parts; branches up to 2 m. long, sometimes woody at the base.

Morphology Leaves

Leaves unequal, the larger up to 6 cm. long (usually somewhat smaller) with up to 8 pairs of leaflets; the smaller up to 3·5 cm. long (usually much smaller) with up to 6 pairs of leaflets; leaflets 4–15 × 1·5–7 mm., rather oblique, oblong, oblong-lanceolate or lanceolate-ovate, acute or subobtuse, villous on both surfaces or nearly glabrous.

Morphology Leaves Stipules

Stipules up to 10 mm. long, linear or linear-lanceolate, acute.

Morphology Reproductive morphology Inflorescences Peduncles

Peduncle usually shorter than, or as long as the subtending leaf.

Morphology Reproductive morphology Flowers Calyx

Sepals 3–6 mm. long, linear-lanceolate, usually villous outside.

Morphology Reproductive morphology Flowers Corolla

Petals light yellow, 3–8 (12) mm. long, broadly cuneate, usually shorter than or as long as or sometimes up to 2·3 times the length of the sepals.

Morphology Reproductive morphology Flowers Androecium Stamens

Filaments about 3 mm. long; anthers 0·5–1 (1·2) mm. long.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Style very short; stigma 0·8–1·2 mm. long, hemispheric, mostly asymmetric and nearly sessile on the ovary.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary with stiff bulbous-based hairs.

Morphology General Glands

Intrastaminal glands not connate.

Morphology Reproductive morphology Fruits

Fruit breaking up into 5 cocci, each with 2 ± strong divergent spines in the upper and 2 smaller ones in the lower part, usually crested on the back, tuberculate and strigose.

M. Thulin. Flora of Somalia, Vol. 1–4 [updated 2008] https://plants.jstor.org/collection/FLOS

Distribution

Tropical and subtropical regions throughout the world.

Morphology General Habit

Pubescent to villous annual-Leaves 2–6 cm long; leaflets 5–8 pairs, oblong to lanceolate, usually 4–18 x 1.5–5 mm; stipules linear to lanceolate, up to 8 mm long

Morphology Reproductive morphology Flowers Pedicel

Pedicel 5–10 mm long

Morphology Reproductive morphology Flowers Calyx

Sepals linear-lanceolate, 3–6 mm long

Morphology Reproductive morphology Flowers Corolla

Petals yellow, 4–8 mm long

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 8–10; filaments up to 3 mm long

Morphology Reproductive morphology Flowers Gynoecium Style

Style very short or absent; stigma ± pyramidal, c. 1 mm long

Morphology Reproductive morphology Fruits

Fruit disc-shaped; pedicel c. 10 mm long; mericarps 4–5 x 2–3 mm, with 2 pairs of spines.

Zygophyllaceae, M. Nabil El Hadidi (Faculty of Science, Cairo University). Flora of Tropical East Africa. 1985

Morphology General Habit

Annual ± pubescent, villous or hispid herb; branches prostrate, up to 90 cm. long; internodes up to 6 cm. long, 2-3 mm. in diameter.

Morphology Leaves

Leaves 3-6 cm. long; leaflets 5-8 pairs, oblong to lanceolate, 4-8 × 1.5-5 mm.; stipules linear to lanceolate, up to 8 mm. long.

Morphology Reproductive morphology Flowers

Flower medium-sized, up to 15 mm. across; pedicel 5-10 mm. long, shorter than the subtending leaf.

Morphology Reproductive morphology Flowers Calyx

Sepals linear-lanceolate, 3-6 × 1-2 mm., deciduous.

Morphology Reproductive morphology Flowers Corolla

Petals lemon-yellow to orange-yellow, 4-8 × 3-6 mm.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 8-10 in 2 whorls; filaments up to 3 mm. long; anthers 0.5-1 mm. long.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary globular, 1 mm. across; style very short or absent; stigma pyramidal, 0.8-1.2 mm. long.

Morphology Reproductive morphology Fruits

Fruit disc-shaped; stalk ± 1 cm. long; mericarp 4-5 × 2-3 mm., provided with 2 pairs of spines.

Habitat

Open and disturbed places, often on sandy soils, becoming a troublesome weed; 0-2300 m.

Distribution

K1 K2 K3 K4 K5 K6 K7 T1 T2 T3 T4 T5 T6 T7 tropical and temperate regions throughout the world